10 Unsolved Mysteries of Science

Listversers love mysteries, but while it seems that we have already covered tons of them, there are always more out there to discover. This time around we have focused on the mysteries of science, that have baffled researchers and left them wondering if current science is unable to grasp them, or even if perhaps there is a higher power at play. Below are ten scientific mysteries that will provoke thought and leave you wanting for the solution. Perhaps someone among us will one day solve some of these mysteries and become a famous scientist renowned for their discovery. For the time being, however, the solution to these equations has not yet been definitively proven or understood.


The theory of Continental Drift was first proposed in 1500 and stated that Continents seem to drift relative to each other across the ocean. Later on it was refined into the theory of Plate Tectonics which proposes that there are tectonic plates on the ocean floor that slowly move separating the continents and creating the Oceans over the time period of millions of years. The mystery, however, is what actually caused these plates to move in the first place and has been further confounded by studies that have shown it is unlikely that the theory actually fully explains the phenomenon. Some have suggested that the due to the unexplained nature of the workings behind the theory, and evidence against it, that the continents may have actually been separated much more quickly than many millions of years, by a catastrophic event such as a flood.

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There were once many other large animals like the Elephant that walked the earth, such as the Wooly Mammoth, these were called Megafauna. The Megafauna for the most part disappeared only recently, in the range of tens of thousands of years ago, and scientists have been unable to truly ascertain why. Two main answers have been suggested as the cause, over hunting by man and climate change. Those who say it is climate change often have very little evidence besides claiming that there isn’t enough evidence for the other explanation. As for the over hunting explanations, many scientists say that even if it were true, there may be very little archeological evidence for it. The Mystery still remains unsolved, and it may never be conclusively understood, there could even be something else entirely at play.


The Mpemba effect is that boiling water can, under certain circumstances, not only freeze but do so quicker than colder water. This phenomenon has been reported as working as far back as Ancient Greece, even though it would seem contradictory to the Laws of Thermodynamics. In 1969 a scientist named Mpemba did experiments that proved that the effect is real, however, scientists are left with more questions than answers. Many solutions have been suggested as reasons for this phenomenon, but none have been agreed upon by scientists and most contradictory explanations were obtained by very different experiments with different controls. Perhaps someday after more study scientists will understand this, but currently the results are inconclusive at best.


While the studies on the speed of light have not fully disproven the theory that it is the fastest we can go, there is increasing evidence that it might actually not be accurate. Some point out that dark energy seems to go at a faster rate than ever as time goes on. They also have observed that if the Big Bang theory is correct, the universe expanded way quicker than light speed when the cosmos were in their infancy. Some scientists in carefully controlled experiments have even managed to clock pulses that actually beat out the speed of light. While how or why we may be able to go faster than light speed is not yet certain, it seems that we may not be as limited as we previously thought. So far this mystery remains unsolved, but science seems to be getting closer to an answer.


People have been reporting strange experiences when they were close to death, and sometimes at other times as well, where they felt that their consciousness had left their body, although their body was still alive. One group of researchers sought to test this out of body feeling. They used virtual reality and cameras, first touching someone’s virtual projected body and their real one, and then just the virtual one. People were convinced that they were being touched even when they were not. The experiment led them to believe that people’s ability to experience things in their body relies greatly on where they believe their body to be visually. Another researcher has sought to understand near death experiences, studying them at a hospital over several years using various controls. He believes his experiment will be able to prove whether people are experiencing illusions, or whether their consciousness is actually leaving the body. While none of this has been proven for certain yet, it would make the religious idea of souls much more believable.


In Arkansas about a year ago, a bunch of black birds fell from the sky. At the time fireworks were blamed, though this theory was not incredibly well tested. It happened again not that long after, and this time they weren’t sure enough to blame fireworks. To make matters even stranger, in the same state, around the same time, thousands of fish mysteriously turned up dead. While a variety of explanations have been given, it’s hard to explain why thousands of birds would fall from the sky, and thousands of fish would suddenly die in the same area around the same time. It could just be a coincidence, but it’s certainly a very odd one.

Scientists were attempting to study early stars but in 2006 they ran into a problem, they were faced with a mysterious noise that greatly inhibited their study. Scientists are left baffled as to what causes this. While sounds cannot travel through space, radio waves can, which is what they believe it is, however they are baffled as to where or what the radio waves are coming from. Also of note is that this sound is six times louder than should be expected, and there is no explanation for that either. Scientists have managed to figure out that it is not any radio waves that they currently know of, or any of the early stars themselves, or any of our dust particles.

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The Moon Illusion has existed since Ancient times, back in the days of Aristotle and the Ancient Greeks and Chinese. The illusion is that the moon seems to appear much larger lower in the sky than it is higher in the sky. In the past people have suggested things such as an atmospheric effect, or something physical, but these have been debunked. Others have suggested such things as relative size, or apparent distance as explanations for this illusion, yet this still baffles scientists. So far no one, even with modern science, has been able to definitively explain this mysterious phenomenon.


People have argued for a long time whether light is a wave or a particle, however, after much study scientists seem to be coming to the conclusion that things are way more confusing than that. Scientists performed studies which seem to show that a photon can act as a wave and a particle at the same time. However, they also have found studies showing that a photon will choose to be a wave or a particle only when forced to make the decision under controlled conditions. So far scientists have no explanation for why this works, and are still trying to understand it. Some have even called it “the one true mystery of Quantum Mechanics”.


The origin of life and the creation of our universe has been the subject of incredible debate and study since recorded history. Some scientists explain the creation of the universe by the model of the Big Bang, which most of us learned in school. Much study has also been done on the subject of Abiogenesis, which is the ability of life to come from matter that is inorganic, the only way for life to be created without prior life. Despite an incredible amount of scientific study, none of this has thus far been proven, although scientists at the Large Hadron Collider project are working on discovering the Higgs Boson, which many believe would bring physicists closer to proving the Big Bang and other parts of the universe’s origin theories.

However, it is important to note that discovering the Higgs Boson is not the be all and end all, it would open up new ground in the study of physics, but it would not definitively prove the Big Bang. Furthermore, many who believe in the theory of intelligent creation would say that even if the Big Bang were to be proven, it does not necessarily mean that a God of some sort is not involved. A god could have created the universe and set it in motion through means that could be observed by science. Those who propose this theory bring up Thomas Aquinas’s famous argument in regards to an unmoved mover, that there had to be some first cause to the events that created the universe. The universe is huge and expansive, and the origins of life may never be fully understood.

Read more: http://listverse.com/2013/02/28/10-unsolved-mysteries-of-science/

Top 10 Facts Surrounding Comet Elenin

One of the biggest viral news stories of 2011 was the discovery of Comet Elenin (C/2010 X1). For a wide variety of reasons, people began to think the comet posed a threat to Earth. Articles were written that examined Elenin. People were intrigued by the comet and its close approach to the Earth in October, 2011. Some predicted Comet Elenin was a sign that the Maya prophecy was valid. In response to the attention, NASA was forced to give a collection of statements. They said the comet posed no threat to the Earth. On August 19, 2011, the story burst into flames and quickly disappeared. Here are ten interesting facts about Comet Elenin.


In ancient history, comets were traditionally considered to be bad omens. They are small Solar System bodies (SSSB) that will display a visible coma (a thin, fuzzy, temporary atmosphere) when close to the Sun. The main difference between an asteroid and a comet is that a comet shows a coma. Asteroids are also thought to have a different origin from comets, having formed inside the orbit of Jupiter rather than in the outer Solar System. This gives the orbital history of comets more importance.

The coma of a comet is formed when it passes by the Sun. The coma is generally made of ice and dust, and can grow to be incredibly large. In October 2007, comet 17P/Holmes briefly had a tenuous dust atmosphere larger than the Sun. It has been estimated that roughly one comet is discovered each year that is visible to the human eye. In some rare cases, a Great Comet can form which is brighter than any star in the sky. It has been estimated that one Great Comet will appear every decade.

The requirements for a Great Comet include a large and active nucleus, a close approach to the Sun, and a close approach to the Earth. In 1996, Comet Hyakutake, which had a similar sized nucleus as Comet Elenin, made an extremely close approach to Earth. The Ulysses spacecraft crossed the Hyakutake’s tail at a distance of more than 500 million kilometers (3.3 AU or 3×108 mi) from the nucleus, showing that Hyakutake had the longest tail known for a comet.


On December 10, 2010, an amateur Russian astronomer named Leonid Elenin discovered a long-period comet in the U.S. state of New Mexico. The near-earth object was given the name of Elenin and was estimated to be 3-4 km in diameter. Almost immediately after the discovery was announced, articles began to appear on the Internet that claimed the comet was dangerous to Earth. People began to make connections between Elenin and extinction level events.

It was originally estimated that the comet would pass within .24 Au (Astronomical Units) of the Earth, which is pretty close. The distance is closer than the Hale-Bopp Comet of 1997, which gained more media attention. The story reached a larger audience after it was disclosed that while using the JPL Horizons system with an observed orbital arc of 235 days, the comet shows an orbital period of approximately 11,800 years. In the history of Earth, 12,000 years ago was a sensitive time and the bridge between the Pleistocene and Holocene geological epochs.


One of the reasons Comet Elenin has received so much attention is that it holds similarities to the blockbuster movie Deep Impact (1998). For starters, in the movie, the comet is found by a teenage boy named Leo and referred to as Elle (extinction level event). In reality, it was discovered by a young Russian astronomer named Leonid Elenin, who was born in 1981 and 17-years-old when Deep Impact came out. It is a coincidence that a man named Elenin discovered a near-earth comet.

After the discovery was announced, articles began to appear on the Internet with acronyms for ELENIN, including extinction level event, near impact or extinction level event nine (indicating 9 out of 10 on the danger scale or the end of the ninth wave of the Mayan Calendar). Some said 11/9, as in November 9, when the debris tail of Elenin was predicted to be closest to Earth. In Deep Impact, a black U.S. president decides to send a mission to blow up the comet with nuclear weapons. The mission succeeds and the comet is separated into sections. However, a piece still hits Earth. After the impact, the president declares martial law, and reveals that the government has been building underground shelters. In the end of the movie, humanity is spared after the larger comet is demolished.


Since Comet Elenin was discovered, NASA was adamant in the fact that the comet would not come close enough to strike or harm the Earth in any way. People responded by using a collection of hypothetical scenarios for disaster. For example, if Elenin was to hit an asteroid while passing through the Main Asteroid Belt, it could have been thrown off its predicted trajectory and pushed toward an imminent crash with Earth. People began to fear the comet’s massive coma.

By August, 2011, Elenin’s coma exceeded 200,000 km. (124,274 miles). It was predicted that on November 6, 2011, the Earth was going to pass through the comet’s debris tail. People began to make a connection between the comet and its alignment with the earth, sun, and moon. Some felt that the gravitational pull of Elenin caused a collection of earthquakes and geological events. The story reached a new level of popularity after the March 11 Tōhoku earthquake and tsunami because a number of websites had published the date of March 15, 2011 as an alignment event. Comet Elenin was predicted to be closest to Earth on October 16, 2011 and the debris field arrived in early November.


In early August of 2011, NASA decided to get a picture of Comet Elenin, so they rotated the STEREO-B spacecraft and photographed it. In the picture, the comet appears to be a deep blue color. The color has caused people to make comparisons between the object and the ancient Hopi Indian prophecy of the blue star. The legend states, “When the Blue Star Kachina makes its appearance in the heavens, the Fifth World will emerge.” The Maya also have stories of a dangerous blue star. The color of Elenin has caused Richard C Hoagland to suggest it is the Hopi Blue Star, a claim which has spawned a number of articles.

A man named Carl Johan Calleman, who is a Swedish toxicologist that specializes in Maya history, also claims that Comet Elenin was the blue star featured in ancient history. Calleman holds a different interpretation of the Maya Calendar all together. He says that the calendar points to the date of October 28, 2011 (not December 21, 2012) as the most important, a day when people will experience a slow transformation of consciousness and reach a higher unity. Before the discovery of Elenin, Calleman identified the time when the comet passed by earth (end of October, 2011) as the critical time.

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45P/Honda-Mrkos-Pajdušáková is a short-period comet discovered in 1948. The comet has an elliptical orbit of 5.26 years and a nucleus estimated to be 0.5-1.6 kilometers in diameter. On August 15, 2011, Honda made a close approach of only 0.0600 AU (8,980,000 km; 5,580,000 mi) to Earth. On August 19, the same day that Comet Elenin was destroyed by a coronal mass ejection, Honda was studied by the Goldstone Deep Space Network. The network detected echoes from the nucleus of Honda and it became only the fifteenth comet in history to be detected by radar.

After the discovery of Comet Elenin was made public, people began to examine the trajectory of the comet in relation to Honda. It appeared that the two objects would come relatively close to hitting on September 28 or 29 of 2011. For this reason, people began to fear the date and predict earthquakes and disasters for late September. Articles were written that hypothesized that the shifting of Elenin’s path could push it into Honda. 255P/Levy is another comet that was mentioned with Elenin. Levy came within 0.2359 AU (35,290,000 km; 21,930,000 mi) of Earth on January 26, 2012.

Asteroid Near Earth Thumb

Meteors are generated when debris enters and burns up in Earth’s atmosphere. Some astronomers have reported that meteor swarms correspond closely to the orbits of known comets. Meteor showers are not threatening to the Earth because the comet’s tail usually doesn’t hold large objects. On December 28, 2005, a potentially hazardous asteroid was discovered by Robert S. McMillan and named 2005 YU55. It is approximately 400 m (1,312 feet) in diameter and caused concern for NASA.

On November 8, 2011, YU55 passed by Earth at a lunar distance of 324,900 kilometers (201,883 miles). It was the closest pass by a large asteroid since 1976. Another object this size in not predicted to come this close to Earth until 2028. After Comet Elenin started to gain attention, people began to connect it with 2005 YU55 because of the date November 9, 2011 (11/9/11). On this date, the tail of Elenin was predicted to be the closest to Earth, along with 2005 YU55. This has caused some people to speculate that a collision between the two objects was possible.


After Comet Elenin was discovered, many people expected the story to be mentioned in the mainstream U.S. media, but it wasn’t. This caused some to suspect that NASA was keeping secrets. The general significance of Comet Elenin was large. In the United States, NASA has a congressional mandate to catalogue all near-Earth objects that are at least 1 kilometer wide. The impact of such an object would be catastrophic to Earth. Studies show that the United States and China are most vulnerable areas to meteor strikes.

The general rule is that NEOs have an apsis distance of less than 1.3 AU. As of May 2012, 8,971 NEOs have been discovered. Of these, only 91 are near-Earth comets and 8,880 near-Earth Asteroids. This makes the discovery of Comet Elenin rare. Even rarer is how close the remnants of the comet came to Earth on October 16, 2011. It passed at a distance of 0.2338 AU, which is really close in comparison to other famous comets of size.

A number of smaller asteroids have made closer approaches. One of importance was asteroid 2010 AL30, which passed by Earth on January 13, 2010 at the distance of 122,000 km (76,000 mi). AL30 was only 10-15 m (33-49 ft) wide, but if the asteroid had entered the Earth’s atmosphere, it would have created an air burst equivalent to between 50 kT and 100 kT (kilotons of TNT). The Hiroshima “Little Boy” atom bomb had a yield between 13-18kT. This shows how important it is to keep comets of any size away from the Earth’s atmosphere.

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By August, 2011, the visibility of Comet Elenin was around 8.3. The comet followed the predictions of NASA until August 19, 2011, when it was destroyed by a coronal mass ejection (CME). A coronal mass ejection is a massive burst of solar wind. During the event, Comet Elenin disintegrated and broke apart. According to NASA officials, it was a rare occurrence and only 2% of new comets that approach the sun are destroyed in this manner. By mid-October 2011, Elenin made its closest pass to Earth, but was nothing more than a pile of rubble. The object was not visible by even large ground-based telescopes.

The post-disintegration appearance of Elenin was compared to the debris field of Shoemaker-Levy 9, which was abundant. The remnants of the comet will “act as other broken-up comets act. They will trail along in a debris cloud that will follow a well-understood path out of the inner solar system. After that, we won’t see the scraps of comet Elenin around these parts for almost 12 millennia.”

With all the controversy surrounding Elenin, the unusual destruction of the comet has caused a lasting image. In the week prior to the coronal mass ejection, articles were posted online that suggested the European Space Agency had a plan to destroy an asteroid headed toward Earth. Specifically, the website of the Daily Mail posted an article titled Fact following fiction? Scientists plan mission to blow up an asteroid hurtling towards Earth. The article was last updated on August 18, 2011, one day before Elenin was destroyed. It discussed the Don Quijote space probe. The probe could be used to study the effects of crashing a spacecraft into an asteroid.


NASA has released a collection of statements regarding Comet Elenin. In each case, the organization has downplayed the importance of the object and its potential impact on Earth. After the comet was destroyed in space, Don Yeomans of NASA said: “I cannot begin to guess why this little comet became such a big Internet sensation. The scientific reality is this modest-sized icy dirtball’s influence upon our planet is so incredibly minuscule that my subcompact automobile exerts a greater gravitational influence on earth than the comet ever would.”

Yeomans explains how the destruction of the comet was a rare, but possible: “comets are fragile and loosely held together like dust balls, so it doesn’t take much to get a comet to disintegrate, and with comets, once they break up, there is no hope of reconciliation.” The stance of NASA is that they don’t want to talk about Elenin because it doesn’t deserve mention in comparison to other problems. Yeoman is quoted: “Comet Elenin has rung down the curtain and joined the choir invisible. This is an ex-comet.”

Read more: http://listverse.com/2012/05/22/top-10-facts-surrounding-comet-elenin/

10 Ways The Quest For Alien Life Is Getting Real

NASA predicts that we’ll find life outside our planet, and possibly outside our solar system, within a generation. But where exactly, and what type of life? Is it even wise to make contact with extraterrestrials? The search hasn’t been easy, but these questions may not be theoretical much longer. Here are 10 ways the quest for alien life is getting real.

10NASA Predicts Alien Life Will Be Found Within 20 Years


In the words of Matt Mountain, director at the Space Telescope Science Institute in Baltimore, “Imagine the moment when the world wakes up, and the human race realizes that its long loneliness in time and space may be over . . . It’s within our grasp to pull off a discovery that will change the world forever.”

Using ground and space-based technology, NASA scientists predict that we’ll find alien life in the Milky Way galaxy within the next 20 years. Launched in 2009, the Kepler Space Telescope (pictured) has helped scientists find thousands of exoplanets (planets outside our solar system). Kepler discovers a planet when it crosses in front of a star, causing a small drop in the star’s brightness.

Based on data from Kepler, NASA scientists believe that in our galaxy alone, 100 million planets may be home to alien life. But it’s the upcoming James Webb Space Telescope (scheduled for a 2018 launch) that will first give us the capability to indirectly detect life on other planets. The Webb telescope searches for gases in a planet’s atmosphere that are generated by life. The ultimate goal is to find Earth 2.0, a twin to our own planet.

9The Alien Life We Find May Not Be Intelligent


The Webb Telescope and its successors will search for biosignatures in the atmospheres of exoplanets, such as molecular water, oxygen, and carbon dioxide. But even if a biosignature is detected, it won’t tell us whether the life on that exoplanet is intelligent or not. Such alien life may be single-celled organisms like amoebas, rather than complex beings that can communicate with us.

We’re also limited in our search for life by our prejudices and lack of imagination. We assume there must be carbon-based life like us, and that we’re the standard by which intelligence is judged. Explaining this failure in creative thought, Carolyn Porco of the Space Science Institute says, “Scientists don’t go off and think completely wild and crazy things unless they have some evidence that leads them to do that.”

Other scientists such as Peter Ward, coauthor of Rare Earth: Why Complex Life Is Uncommon in the Universe, believe that intelligent alien life will be short-lived. Ward assumes that other species will have global warming, too many people, no food, and eventual chaos that destroys their civilizations. He foresees the same for us.

8Mars May Have Supported Life Before—And May Again


Mars is currently too cold to house liquid water and support life. But NASA’s Opportunity Rover—an all-terrain vehicle that collects and analyzes rocks on Mars—has shown that about four billion years ago, the planet had fresh water and mud that could have supported life.

Another past source of water and possible life sits on the slopes of Mars’s third-tallest volcano, Arsia Mons. Around 210 million years ago, this volcano erupted beneath a vast glacier. The volcano’s heat caused the ice to melt, forming lakes in the glacier like liquid bubbles in a partially frozen ice cube. The lakes may have existed long enough for microbial life to have formed there.

It’s possible that some simple organisms on Earth may be able to survive on Mars today. Methanogens, for example, use hydrogen and carbon dioxide to produce methane, and don’t need oxygen, organic nutrients, or light. They’re able to survive temperature extremes such as those found during Martian freeze-thaw cycles. So when scientists found methane in Mars’ atmosphere in 2004, they questioned whether methanogens already inhabit the subsurface of Mars.

As we travel to Mars, though, scientists are concerned that we may contaminate the planet’s environment with microorganisms from Earth. That may make it difficult to determine whether life forms found on Mars originated there.

7NASA Plans To Search For Life On Jupiter’s Moon


NASA is planning to launch a mission in the 2020s to Europa, one of Jupiter’s moons. One of its high priorities is determining if the moon’s surface is habitable and identifying locations where future missions may land a spacecraft.

In addition, NASA is on the search for life (possibly intelligent) beneath the moon’s thick, icy surface. In an interview with The Guardian, NASA’s chief scientist Dr. Ellen Stofan said, “We know there is an ocean under that icy crust. There are plumes of water coming out of the cracks in the south polar region. There’s orange gunk all over the surface—what the heck is that stuff?”

The spacecraft sent to Europa may either orbit or perform multiple flybys of the moon, possibly flying through those plumes of water in the southern region. That would let us collect samples of Europa’s inner layers without the risk and high cost of landing the spacecraft. But any mission must protect the spacecraft and instruments from the high-radiation environment. NASA also wants to ensure that we don’t contaminate Europa with organisms carried from Earth.

6Exomoons May Be Detected Through Radio Emissions


Until now, scientists have been technologically limited in their search for life outside our solar system to exoplanets. But physicists from the University of Texas believe they’ve discovered a way to detect exomoons (moons orbiting exoplanets) through radio emissions. This may greatly expand the number of habitable bodies on which we may find alien life.

Using their knowledge of radio emissions caused by the interaction between Jupiter’s magnetic field and the planet’s moon Io, these scientists have extrapolated formulas to search for radio emissions from exomoons. They also believe that Alfven waves (the rippling of plasma caused by the interaction between a planet’s magnetic field and its moon), may help us spot exomoons in a similar way.

In our solar system, moons such as Europa and Saturn’s Enceladus have the potential to support life based on their distance from the Sun, their atmosphere, and the possible existence of water. But as our radio telescopes get more powerful and more advanced, scientists hope to conclusively study more distant bodies.

Currently, two exoplanets with possible exomoons are the main candidates for hosting life: Gliese 876b (approximately 15 light-years away) and Epsilon Eridani b (approximately 11 light-years away). Both are gas giants (as are most exoplanets we’ve discovered), but many are in the habitable zones of their stars. Any exomoons orbiting these planets may have the potential to support life.

5Advanced Alien Life May Be Detected By Pollution


Until now, scientists have searched for alien life by looking for exoplanets rich in gases like oxygen, carbon dioxide, and methane. But since the Webb Telescope should be able to detect ozone-destroying chlorofluorocarbons, some researchers now suggest we consider looking for industrial pollution to find advanced alien life.

While we hope to detect an alien civilization that’s still alive, it’s very feasible that we might find an extinct culture that destroyed itself. Scientists believe the best way to tell if a civilization still exists is by searching for both long-lived pollutants (that stay in the atmosphere for tens of thousands of years) and short-lived pollutants (that last only a decade or so). If the Webb Telescope detects only long-lived pollutants, then the alien civilization may be extinct.

But this method does have its limitations. The Webb Telescope can so far only spot pollutants on an exoplanet orbiting a white dwarf (the remnant of a dead star, roughly the size of our Sun). Dead stars typically equal dead civilizations, so the search for actively polluted life might have to wait until our technology grows even more advanced.

4Oceans May Make Exoplanets More Habitable


To determine which planets may support intelligent life, scientists usually focus their computer models on the atmospheres of planets within a star’s habitable zone. But new research suggests that our models should also factor in the impact of large, liquid oceans.

Let’s use our own solar system as an example. Earth has a stable environment that supports life, but Mars—on the outer edge of our habitable zone—is frozen. It has temperatures that may fluctuate by over 100 degrees Celsius (212 °F). Then there’s Venus, on the inside edge of our habitable zone and scorching hot. Neither planet is a good candidate to support intelligent life, though they may host microorganisms that can survive in extreme environments.

Unlike Earth, neither Mars nor Venus currently has a liquid ocean. According to David Stevens of the University of East Anglia, “Oceans have an immense capacity to control climate. They are beneficial because they cause the surface temperature to respond very slowly to seasonal changes in solar heating. And they help ensure that temperature swings across a planet are kept to tolerable levels.” That’s why Stevens believes we should factor the presence of oceans into our models when searching for alien life.

3‘Tilt-A-Worlds’ May Expand Habitable Space


Exoplanets with fluctuating tilts in their orbits may support life in places where fixed-spin planets like Earth couldn’t. That’s because these “tilt-a-worlds” have a different relationship to the planets around them.

Earth and its planetary neighbors circle the Sun on about the same plane. But tilt-a-worlds and their neighboring planets orbit at angles, tugging at each other’s orbital planes in a way that occasionally spins a tilt-a-world’s poles toward its host star. The spinning may resemble the wobbling of a child’s top when rotating at a slow speed.

Tilt-a-worlds are more likely than fixed-spin planets to have liquid surface water. That’s because the heat from a host star is more evenly distributed on the surface of a tilt-a-world, especially when its poles are turned toward its sun. The planet’s ice caps will melt quickly, creating surface water and making the planet more likely to support life. This characteristic of tilt-a-worlds may expand the edge of a star’s habitable zone by 10 to 20 percent past the point where fixed-spin planets would freeze over.

2Eccentric Exoplanets May Host Extreme Life Forms


For the most part, astronomers search for life on exoplanets that reside within their star’s habitable zone. But some “eccentric” exoplanets remain in the habitable zone only part of the time. When outside the zone, they may experience molten hot or frigid temperatures.

Even so, these planets may still support life. Scientists point to certain microscopic life forms on Earth that can live in extreme conditions—both on Earth and in space—such as bacteria, lichen, and spores. This suggests that a star’s habitable zone may extend farther than initially believed. But we have to change our thinking to include planets hostile to life on Earth, but favorable to life forms that thrive in, or at least tolerate, harsh conditions.

1Researchers Question Whether We’re Ready For Contact With Alien Life


NASA is taking an aggressive approach to finding alien life in our universe. The Search for Extraterrestrial Intelligence (SETI) project has also become more ambitious in its efforts to contact alien civilizations. SETI wants to move beyond the mere searching and tracking of extraterrestrial signals, and start actively sending messages through space to identify our position to others.

But contacting intelligent alien life may be a danger we’re not prepared to handle. Stephen Hawking has warned that a superior civilization would most likely use their power to dominate us. There is also concern that NASA and SETI are overstepping ethical boundaries. As neuropsychologist Gabriel G. de la Torre asks, “Can such a decision be taken on behalf of the whole planet? What would happen if it was successful and ‘someone’ received our signal? Are we prepared for this type of contact?”

Based on a survey of college students, de la Torre believes that the general public currently lacks the knowledge and preparation needed to deal with intelligent alien contact. Most people’s viewpoints are also influenced by their religious beliefs.

+The Search For Alien Life Isn’t As Easy As We Thought

Planets Under a Red Sun

The technology we use to hunt down alien life has greatly improved, but the search still isn’t nearly as easy as we originally thought. For example, biosignatures are generally believed to be evidence of life, either past or present. But scientists have discovered lifeless planets with lifeless moons that yield the same biosignatures that we typically see as evidence of life. This means our current methods for detecting life on exoplanets may easily produce false positives.

In addition, the existence of life on other planets may be far more unlikely than we thought. Red dwarf stars, which are smaller and cooler than our Sun, are the most common stars in our universe. But our latest information shows that exoplanets residing in a red dwarf’s habitable zone may have their atmospheres destroyed by extremely harsh weather.

Read more: http://listverse.com/2014/08/17/10-ways-the-quest-for-alien-life-is-getting-real/

10 Unique Stories Of Milestone Meteorites

Every day, our atmosphere is bombarded with alien rocks. They travel billions of miles across the soulless chasm of space on a collision course with Earth, and in a brief, glorious instant, they’re gone, burned to oblivion in the upper reaches of the atmosphere. But every now and then, a meteorite arrives with just the right mixture of size and determination to make landfall. And if it wasn’t a rock, it would understand that this means exciting times for the people below.

10 An Ancient Undiscovered Mineral


The Krotite meteorite was discovered in Morocco in 1934, lending it the official name of “NWA 1934.” The small rock had few distinguishing features, but there was one problem: Nobody could figure out what it was made of. It wasn’t until 2010 that researchers came to the conclusion that the meteorite contained a completely new mineral that had never been seen before.

The mineral was named “krotite” after Alexander Krot, the cosmochemist who worked on figuring out the chemical composition of the rock. Interestingly enough, krotite is extremely similar to a few different forms of man-made concrete, just further proof that anything we can make, nature’s probably already figured out. And in this case, nature figured it out about 4.6 billion years ago—krotite is believed to be one of the oldest minerals, having formed back when the Solar System was still just thinking about coming together.

9A Nuke-Like Blast From An Alien Planet

Most meteorites break off a larger, parent meteoroid well before entering our atmosphere. The Tagish Lake Meteoroid, however, plunged headlong into the stratosphere before shattering with more energy than the bomb that took out Hiroshima. The meteoroid itself was estimated to be 4 meters (13 ft) in diameter with a weight of 56 metric tons, large enough to wreak havoc in a large area if it had landed intact.

As it was, about 93 percent of the meteoroid was ablated, or vaporized, before it erupted into a fireball. It exploded about 40 kilometers (25 mi) above the Earth’s surface and sent thousands of meteorites clattering across the frozen surface of Tagish Lake in Canada. When NASA arrived to study the pieces, they had to cut blocks of ice out of the lake because the fragments were too deeply embedded to remove. The entire lake had been perforated. After studying the meteorites, it was discovered that they had come from 773 Irmintraud, a minor planet (or large asteroid) that floats between Jupiter and Mars.

8Mars’s History Revealed

Until 2005, all the meteorites ever studied had been found on Earth (not counting two on the Moon). We hadn’t really been anywhere else. But a year after the Opportunity rover landed on Mars in 2004, it discovered the first meteorite to be found on another planet. The discovery was an accident; the rover was looking for the heat shield that had been ejected during its landing. Sitting next to the shield was large, pocked ball of iron—the Heat Shield Rock.

Since the rover wasn’t equipped to drill into something made of almost pure iron, we haven’t been able to study it much. But one thing is certain—due to the way it survived its fall intact, it must have been traveling fairly slowly. To do that, Mars must have had a much thicker atmosphere when it fell, an atmosphere that contained water. This brings us we closer to figuring out the timeline of the changes in Mars’s atmosphere, something we’ve never really been able to do. And all it took was a chunk of rock.

7Liquid Water On Mars

Most meteorites are very old. Solid chunks of matter were typically formed a few billion years ago, and the ones that didn’t coalesce into a planet became nomads, drifting aimlessly through space. For example, the Allan Hills 84001 meteorite (or ALH84001) is believed to be over 4 billion years old —a relic from the formation of our Solar System.

But it’s not famous for being one of the oldest things in our neighborhood. Discovered in Antarctica in 1984, ALH84001 was studied extensively for eight years before researchers made a shocking announcement: It was covered with carbonate globules, a sign that it could be a collection of bacteria fossils. That’s particularly strange, considering it came from Mars. It’s believed that about 15 million years ago, the impact from another meteorite knocked this chunk into space, along with a colony of Martian bacteria. It floated around in space for a while before connecting with our planet roughly 13,000 years ago.

The claim that the rock was covered in alien bacteria was later bashed to bits by the scientific community. But in 2011, it was confirmed that even if bacteria never lived on the rock, it was definitely formed in an environment with liquid water.

6A Sign From God


The Ensisheim meteorite is the oldest preserved meteorite in the world. It landed in 1492 in Ensisheim, a small village in eastern France. The rock itself isn’t really anything spectacular. It’s what’s known as an ordinary chondrite which, as you might guess from the name, isn’t the rarest thing that’s ever fallen from the sky. Ordinary chondrites make up nearly 90 percent of all meteorite finds.

But in the 15th century, the Ensisheim caused quite a stir. Accounts of the meteorite describe it as a falling inferno, a fireball that could be seen more than 150 kilometers (93 mi) away. Locals were quick to chalk it up as a sign from God, and the meteorite was immediately excavated, carted into town, and chained inside the Ensisheim church. Pieces of the meteorite were then chipped off and sent to the Holy Roman Emperor and Pope Pius III. The meteorite was even commemorated in songs and poems from the era.

5 The Iron Monument


With a weight of more than 60 tons, the Hoba meteorite is the largest known meteorite in the world. As a matter of fact, it’s also the largest single piece of iron that we know about. Because it’s so massive, it’s never been moved—it’s still sitting in a little farm near Grootfontein, Namibia.

The Hoba meteorite was discovered by pure luck. A Namibian farmer, Jacobus Brits, was whipping his ox through a field on his property when the plow came to a screeching halt. Upon investigating, he found a large, square rock embedded in the dirt. It wasn’t until later that he realized it was a meteorite. Because of its shape (flat on all sides), it’s believed that the meteorite skipped across the surface of the atmosphere a few times, like a pebble skipping across a pond, before plunging through. It probably made landfall around 80,000 years ago, crashing through the atmospheric layers at speeds of 300 meters per second (about 1,000 ft/s). It’s now a national monument.

4A Car-Wrecking Fortune


In 1992, thousands of Pennsylvania residents watched a flaming green object hurtle through the sky and come to a thundering halt in the trunk of a Chevy Malibu. Aside from the meteorite which fizzled through Russia’s skies in 2013, the Peekskill meteorite, as it was later named, is the most recorded meteorite in history. As it crossed over a high school football game, dozens of parents forgot their children and turned their video cameras to the heavens to get it on film. Sixteen videos later surfaced showing the meteorite’s descent.

The meteorite, which weighed 12 kilograms (26 lbs), was a rare type known as an H6 monomict breccia—it was formed when two massive asteroids collided in space, creating an enormous amount of pressure and heat. Before it hit the atmosphere, it was rocketing through space at 14,000 meters (8.8 mi) per second—by the time it landed 40 seconds later, it had slowed down to only 200 kilometers (126 mi) per hour.

But what about the car? Well, the owner was able to purchase a new one after selling the meteorite for the tidy sum of $69,000.

3Diamonds And The Seeds Of Life


Right now, 28 high-powered telescopes orbit the Earth. Dozens of land-based observatories are scattered across the globe, and untold millions of amateur telescopes point towards the stars. The goal of all of these is simple: to see things in space. But until 2008, we had never caught a meteorite until it was already burning a trail through the atmosphere, completely visible with the naked eye. 2008 TC3 was the first meteorite that was tracked to Earth from outer space, and despite all our technology, the feat boiled down to nothing more than a hobbyist who happened to be looking in the right place at the right time.

Richard A. Kowalski spotted the asteroid a full 19 hours before it reached the planet. NASA quickly jumped in and, with an army of amateur astronomers at their backs, calculated the exact landing position of the rock. Sure enough, the asteroid broke up in the atmosphere and showered hundreds of meteorites across the Nubian Desert in Sudan.

But the real surprise came later—far from being a normal rock, 2008 TC3 was filled with nanodiamonds, diamonds with an extremely small crystalline structure which are the hardest material in the known universe. And spread across the surface of the nanodiamonds was another, stickier surprise: amino acids, the building blocks of life. This proves that life can technically form in space, and by all probability, life on Earth started after a similar meteorite impact.

2An Extraterrestrial Killer


In October 1972, the first meteorite fatality in known history was recorded in the small village of Trujillo, Venezuela. The victim: a dairy cow. Nobody saw the meteorite fall, but the sound was unmistakable—a massive sonic boom that’s caused when a meteor explodes into fragments in the upper atmosphere.

The next morning, the owner of the farm, Argimiro Gonzalez, was woken up by one of his farm hands. The man was babbling about killer rocks, and when Gonzalez investigated he indeed found a bloody rock in one of his fields. Beside the rock was a very dead cow, its shoulders and neck crushed to a pulp like the trunk of a Chevy Malibu. The cow was promptly eaten, and Gonzalez used the murderous mineral as a doorstop for the next several years, until an astronomer came to examine it and declared it to be a fragment of the Valera meteorite that had broken up over Venezuela around that time.

You can actually buy the meteorite now and own the only alien object to claim the life of an Earth creature on our home turf.

1 The (Supposed) Cure For AIDS


On August 14, 1992, a meteorite shower hit the village of Mbale, Uganda. The meteorite was nothing special, just run-of-the-mill ordinary chondrite, a big, ugly rock that only weighed 1,000 kilograms (2,200 lbs) before routinely shattering into fragments. Boring.

But by the time researchers arrived at the site, there wasn’t much left to study—the local population had already crushed most of the pieces into powder and eaten it. See, Mbale at that time was going through an AIDS epidemic that was sweeping through the populace. Desperate, they took the meteorite as a sign from God, and believed that within its cosmic structure was a cure for the disease with which they were stricken. They were swallowing the powder by the fistful and mixing it with water to form a paste, which they smeared over their skin.

Unfortunately, there was nothing in the meteorite except for some chunks of iron, and AIDS still affects that region of Uganda to this day.

Read more: http://listverse.com/2014/01/04/10-unique-stories-of-milestone-meteorites/

10 Record-Breaking Objects In Space

While humanity has certainly accomplished some impressive feats, it turns out that we’re still small fry compared to the rest of the universe. Space’s entries in the “most extreme things” contest take all of the medals—and then destroy them in a variety of spectacular ways.

10Most Powerful Lens


Einstein’s General Theory of Relativity has a number of implications. Amongst them is the idea that light doesn’t always go in a straight line. Space itself, through which light travels, bends around any object with mass. The more massive the object, the more space bends. What that means is that when light flies past a star, for example, it will curve towards the star and change direction. One result of this is an effect known as Einstein rings. If a body is shining its light out in all directions behind a massive object, the light will all bend towards the massive object and form the illusion of a ring to us on the other side.

The largest cosmic lens ever found has the memorable name of J0717.5+3745. It’s the most crowded galactic cluster ever found, described as a “cosmic free-for-all” 5.4 billion light years from Earth. These lensing effects are useful for studying things in the universe that have mass but don’t emit radiation. We just need to look for the lensing effect in areas where there’s no regular matter to explain it. Scientists were able to use Einstein rings in J0717.5+3745 to map out its dark matter and have produced a picture with the additional mass added in false color.

9 Most Powerful X-Ray Blast


The most powerful X-ray burst ever seen was picked up by NASA’s Swift telescope in June 2010. The blast, which had come from five billion light years away, was bright enough to overwhelm the satellite to the point where its data processing software simply shut down. One of the scientists that worked on the project described it as like “trying to use a rain gauge and a bucket to measure the flow rate of a tsunami.”

The blast was 14 times brighter than the strongest continuous X-ray source in the sky, but that source is a neutron star that is 500,000 times closer to Earth. The cause of the intense burst is a star morphing into a black hole, yet scientists didn’t ever expect to see anything quite this bright. Curiously, even though the X-ray emissions were record-breaking, emissions in other spectrums were perfectly normal.

8 Most Powerful Magnet


The record for strongest cosmic magnet belongs to neutron star SGR 0418+5729, observed by the European Space Agency in 2009. Scientists devised a new technique for processing X-ray emissions that allowed them observe the magnetic field under the star’s surface. The ESA themselves described it as a “magnetic monster.”

Magnetars are pretty small, around 20 kilometers (12 mi) wide. Size-wise, you’d be able to fit one quite easily on the Moon. But it’d probably be best if you didn’t: Even from that distance, the magnetic field would be strong enough to stop a locomotive on Earth. Luckily, this one is 6,500 light years away.

7 Megamasers


Lasers have been pretty useful over the last few decades, so we shouldn’t be surprised that they get all of the good PR. Their cousins from further along the spectrum are called masers, which are the same thing but with microwaves instead of light. The most powerful manmade laser, for comparison, reached a peak power of 500 trillion watts. The universe makes this look like a damp candle, sending out masers with a power of one nonillion watts. In numbers that you’ve heard of, that’s a million trillion trillion—about 10,000 times the power output of the Sun.

Poets will be pleased to learn that masers are produced by quasars, which are large discs of material collapsing into the massive central black holes of distant galaxies. Surprisingly, the source of these most powerful masers is water. The water molecules in the quasar bump into each other, emit microwaves, and cause their neighbors to do the same. This chain reaction amplifies the signal into the masers we see. Masers from the quasar MG J0414+0534 were detected in 2008 and provided evidence of water 11.1 billion light-years away.

6 Oldest Objects Ever Found

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The universe is around 6,000 years old, give or take 13.7 billion. The oldest object whose age we can directly measure is HE 1523-0901, a star in our own galaxy. Measuring the age of a star is done with radioactive clocks in much the same way we use carbon to measure the age of human artifacts. Only elements with a very long half life—such as uranium or thorium—can work over this length of time. Measurements made by the European Southern Observatory in Chile were able to pick up on six different ways of measuring the star’s age, confirming it to be 13.2 billion years old.

There are other objects whose age we can’t measure but can infer. Some of them appear to be even older than HE 1523-0901. HD 140283—nicknamed the “Methuselah star”—is a star that has long caused trouble. Initial estimates of its age gave figures that would make it older than the universe. More accurate measurements made possible by Hubble brought the figure down from 16 billion years to around 14.5 billion, with error bars that bring it inside the age of everything else.

5 Fastest Spinners


Scientists recently created the fastest manmade spinning object, which rotated 600 million times per second. That’s impressive, but the object was only 4 millionths of a meter wide so its surface was travelling at around 7,500 meters per second). That sounds quick (and it is), but it’s peanuts compared to what space can serve up.

VFTS 102 is the fastest spinning star we’ve ever found, and its surface goes upwards of 440,000 meters per second (1 million miles per hour). It’s 160,000 light years away from us in the awesomely named Tarantula Nebula in one of our neighboring galaxies. Astronomers think the star used to have a companion star that went supernova, blasting the survivor into its cosmic twirl.

4 Record-Breaking Galaxies


Unless you get your physics lesson mainly from Will Smith movies, you’ll know that galaxies are all pretty big. Our own Milky Way is 100,000 light years across. You could fit 50 Milky Ways into IC 1101, the largest galaxy ever found. It was first observed in 1790 by William Herschel, and we now know it’s over a billion light years away. That’s quite a distance but still only a fraction of the record for farthest away.

The most distant galaxy ever found is called z8_GND_5296—around 30 billion light years away from Earth. The galaxy is from around 700 million years after the start of the universe itself. (At that distance, it takes light so long to reach us, we’re actually looking back in time). What is curious about the galaxy is its rate of star production, which is hundreds of times faster than that of the Milky Way. The next generation of space telescopes will push our ability to see back in time even farther—to some of the earliest stars formed in the universe.

3 The Coldest Star


There are a lot of words you could use to describe a star: hot, big, bright, very hot, very big, and so on. Yet stars don’t always fit our expectations. The coldest class of stars—brown dwarfs—are actually pretty cool. WISE 1828+2650 is a brown dwarf in the Lyra constellation with a surface temperature of 25° Celsius (80° F), which is 10° C cooler than a person with hypothermia. Often called a “failed star,” it didn’t have enough mass to ignite when it collapsed on itself.

Stars this dim cannot be seen in the visible spectrum. The WISE part of its name is from the Wide-field Infrared Survey Explorer. NASA uses WISE to find brown dwarfs and to gain insights into their formation, and they have to find them in the infrared spectrum. WISE has found over 100 brown dwarfs since it was launched in December 2009.

2The Fastest Meteorite


If you happened to be in California on April 22, 2012, then you might have been lucky enough to see the Sutter’s Mill meteorite blazing through the sky. Seeing a meteor is always cool, but the fireball above the Sierra Nevada foothills on that day was particularly special—it’s the fastest we’ve ever recorded. It was traveling 103,000 kilometers per hour (64,000 mph), almost twice as fast as we’ve ever shot a rocket.

Scientists brought together information from a number of sources, including weather radar, pictures, and videos of the meteor. This allowed them to triangulate its trajectory and figure out not only its speed, but where it came from. They were even able to produce a picture of its orbit. Before hitting Earth it used to travel almost as far out as Jupiter. The gas giant likely launched it towards us.

The meteorite was interesting for other reasons as well. It was made of carbonaceous chondrite, a rare material. These meteorites have been called “time capsules,” as they’ve been almost unchanged since they formed in the early solar system 4.5 billion years ago. Scientists are typically able to track objects in the sky without knowing much about what they’re made of, or analyze a meteorite in a lab without knowing where it came from in space. Having both pieces of information at the same time is of “huge added value,” according to a geologist from Australia’s Curtin University.

1 Fastest Orbits


Binary star systems—where two stars orbit their common center of mass—are quite common. Some of them even have planets and there’s a system with six stars in mutual orbit. However, some of them are going very, very fast.

The fastest orbit of two normal stars around each other is in a system called HM Cancri. These two white dwarfs—the dead remnants of stars like our Sun—are separated by a distance only three times the width of the Earth. They zoom through space at 1.8 million kilometers per hour (1.1 million mph), spraying hot gas at one another and unleashing large amounts of energy. It takes them less than six minutes to complete a full orbit.

More unusual binary pairs have been found that move even faster. Scientists have observed a black hole named MAXI J1659-152 which forms a binary pair with a red dwarf that is just 20 percent the size of the Sun. The black hole orbits relatively slowly, just 150,000 kilometers per hour (93,000 mph). Its companion, however, whizzes around at 2 million kilometers per hour (1.2 million mph). The red dwarf is farther away from their shared center of gravity (otherwise they’d crash into one another), but it’s constantly losing material to the black hole and will eventually be destroyed.

The current record holder for fastest binary orbit goes to a dying star orbiting with a super dense neutron star. The neutron star is the slower of the two, but has the fantastic name “black widow pulsar” to make up for it (its less cool name is PSR J1311-3430). Its orbital speed of just 13,000 kilometers per hour (8,100 mph) is quite slow—Earth goes around the Sun eight times faster. The pulsar’s companion more than makes up for it though, clocking in at 2.8 million kilometers per hour (1.7 million mph).

The “black widow” name given to its companion was chosen because the female black widow spider devours its male after mating. The pulsar is bombarding the star with so much radiation that it (she?) is actually vaporizing it. Eventually, it will destroy the star completely. So, while the binary stars of HM Cancri only take third place in this entry, we’re forced to conclude that they’ve got the healthiest overall relationship.

Read more: http://listverse.com/2013/11/19/revised-10-record-breaking-objects-in-space/

10 Lesser-Known Historic Comets

Seeing one of the incredible comets that pass by the Earth is one of the greatest pleasures in life. If we are lucky, we will get to see several comets while we are here on this planet. Some will be barely visible to the naked eye, while others will be objects as bright as Venus or the Moon. It is the latter that we remember most and to which we give the name “Great Comet of (fill in the year).” Here are 10 of the lesser-known comets that, in one way or another, live up to the title of “great.”

10Comet Bennett

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Probably the best-remembered comet from the 1970s was the very disappointing Kohoutek, which failed to reach its much-anticipated level of brightness in 1973–1974. However, there were two very good comets to grace the skies in the ’70s—Comet West and the lesser-known Comet Bennett. Though seldom mentioned in the same breath as the fantastic Comet West, Comet Bennett put on a spectacular display from February through May 1970.

Comet Bennett was a bright morning comet visible to anyone willing to brave the cold to see it. And it was worth the trouble, as it brightened to magnitude zero. The astronomical magnitude scale is a measure of how bright an object appears in the night sky, with zero being as bright as the summer star Vega. Objects with a negative number are even brighter and easier to see. For comparison, the brightest planet in the night sky is Venus, at -4 magnitude. Comet Bennett had a long, fantastic tail extending behind it, which was actually two tails twisting together. Though it faded from view by mid-May, it is remembered by some astronomers as one of the most impressive comets of the 20th century. Comet Bennett will be back to see us (or rather, for us to see) in 17,000 years.

9The Headless Comet Of 1887

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Viewable for a very short time in the Southern Hemisphere, the Great Southern Comet of 1887 was remarkable for one bizarre reason—it had no nucleus, or “head.” The nucleus is the heart of the comet and is a solid block of ice and other material which is often referred to as a “dirty snowball.” The nucleus creates the coma—the cloud of dust surrounding the nucleus—and that accounts for the dust tail that is “blown” by the solar wind.

How is it possible that the Great Southern Comet of 1887 was so spectacular to see, but did not have a visible coma? Scientists have a few theories as to why the head of the comet may not have shone very brightly, but none of them are entirely conclusive. Whatever the explanation, the lack of a head gave the comet its second name, the “Headless Wonder.” Even though it was not visible for long before it disappeared, it was spectacular to see, with a tail stretching 50 degrees across the night sky.

8Great Comet Of 1861

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In 1910, the world eagerly awaited the return of Comet Halley. By that point, scientists had been able to study the chemical composition of the tail of dust from Halley’s comet and had determined that it contained, among many other chemicals and elements, cyanide gas. Though the amount of cyanide gas was very low, the press spread fears that on May 19, 1910, when the Earth passed through the comet’s tail, the deadly gas would kill all life on Earth. Of course, the night came and went, the Earth passed through the tail of the comet, and the next morning the planet was still full of life.

Forty-nine years earlier, the Earth had another very close encounter with a comet—the Great Comet of 1861, also called Comet Tebbutt after the man who discovered it—farmer and astronomer John Tebbutt. On May 13, 1861, he spotted a fuzzy object in the night sky above the little town of Windsor, near Sydney, Australia. Not recognizing any such nebula or star cluster in that area of the sky, he sent a letter to the Government Astronomer at Sydney University, who verified that Tebbutt had done what few humans ever achieve—find (and be named for) a comet. Tebbutt’s discovery was published in the Sydney paper, and word of the new comet started to spread around the scientific world.

As it slowly moved into the Northern Hemisphere, Comet Tebbutt was visible for most of the summer of 1861. It steadily grew in brightness, eventually reaching magnitude zero, and on June 29th, the Earth passed right through the tail of the comet. It brightened to magnitude -4 (as bright as Venus), with a tail that stretched 120 degrees across the sky. To give you a rough idea of how amazing that is, remember that 90 degrees from the horizontal (the horizon) is the point directly overhead (the zenith). If the head of Comet Tebbutt had been at the horizon, its tail would have arced across the sky well past the zenith. Just as it would in 1910, the Earth survived its close encounter with the tail of the Great Comet of 1861.

7Comet Arend-Roland

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Discovered in 1956, Comet Arend-Roland was the first great comet visible in the Northern Hemisphere since the 1910 appearance of Halley’s Comet, and today it’s thought of as the first great comet of the modern era. In April 1957, the comet passed closest to Earth and brightened into an amazing celestial object with a magnitude of zero and a tail stretching 30 degrees. It then showed a rare site: a bright anti-tail—a tail pointed toward the sun.

In his book Cosmos, astronomer Carl Sagan recollected one of the great stories of Comet Arend-Roland. Sagan was a graduate student attending the University of Chicago when Comet Arend-Roland was visible. He received a phone call one evening from an inebriated man who wanted to speak to a “shtrominer” about why there was a fuzzy ball of light in the sky above his outdoor party. Why did the ball of light disappear when you looked at it, then reappear when you averted your gaze? Sagan explained to the man that he was seeing Comet Arend-Roland. The man asked Sagan, “what’s a comet,” to which Sagan replied, “a snowball one mile across.” Not about to believe such nonsense, the man then asked Sagan if he could speak to “a real shtrominer.”

6Comet Encke

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Comet Encke makes this list for several significant reasons. First, it is the periodic comet with the shortest known orbit around the Sun, only three years. Comet Encke is just one of many periodic comets, most with orbits that will bring the comet past Earth several times during an average human life span. Periodic comets are interlopers from the Oort cloud and Kuiper belt, an area filled with comets and asteroids which lies past the orbit of Neptune. From there, the periodic comets make frequent visits to Earth as they orbit the Sun. Because it comes back to visit our planet on a regular basis, Comet Encke is sometimes referred to as “old faithful.”

But sometimes, the comet is not so friendly to Earth. Some scientists believe that Comet Encke is related to many historical Earth impacts, including the 1908 Tunguska explosion. Some scientists even believe that Comet Encke may be the source of inspiration for the swastika. A rare Chinese comet atlas from the fourth century B.C. was discovered in 1978, and among the many drawings of comets was one with a very recognizable swastika shape.

Had the ancient Chinese observed Comet Encke in 2007, they would have been amazed to find that it had no tail at all—it had “fallen off” after a close encounter with the Sun. Comet Encke is also responsible for the annual Taurid meteor shower in early November, when the Earth passes through the remnants of dust left behind by the comet’s tail.

5Comet Swift-Tuttle

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You may not have heard of Comet Swift-Tuttle, but astronomers and scientists have, and they worry a great deal about this comet. And for good reason—Comet Swift-Tuttle has been called “the single most dangerous object known to humanity.”

Comet Swift-Tuttle is the largest of the periodic comets, those that make regular and relatively short-term visits to our Sun and Earth. It’s an old acquaintance of man. Scientists believe that there have been recorded sightings of its regular 120-year orbit for thousands of years. The last time it was back to see us was in 1992, not 1982 like astronomers expected. We now know its true orbital period, which leads to the problem: The next time Comet Swift-Tuttle is due to return is 2126, not 2116—putting it much closer to the Earth’s orbit. For a time, scientists were actually worried that it might impact the Earth.

The comet’s large nucleus is what gives scientists concern. At over 26 kilometers (16.2 mi) in diameter, Comet Swift-Tuttle rivals the size of previous comets that have hit the Earth—impacts that have destroyed almost all life on the planet. Even though we now know the comet will miss us in 2126, it will be close enough to Earth to provide those lucky enough to see it with a spectacular show in the night sky. And we are still keeping a close eye on the comet, just in case it decides to change its mind between now and 2126.

On a more pleasant note, because it comes back to visit Earth on a routine basis, the Earth regularly passes through remnants of its tail. The dust left behind by Comet Swift-Tuttle creates one of the best and most reliable astronomical events each year—the Perseid meteor shower.

4The Great Comet Of 1811

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Also called Comet Flaugergues, this comet was first seen in April 1811. The comet was visible with either the naked eye or a telescope for an amazing 17 months, spanning well into 1812. At its brightest, Comet Flaugergues was magnitude 1 and had a tail stretching 25 degrees.

While the Great Comet of 1811 was called Comet Flaugergues, it is best remembered as either “Tecumseh’s Comet” in the United States or “Napoleon’s Comet” in Europe. In 1811, people were beginning to look at comets and other astronomical events with less fear and superstition. However, Comet Flaugergues worked hard to overcome that progress by coinciding with the greatest onset of earthquakes in US history—the New Madrid earthquakes, a series of thousands of quakes that spanned from December 1811 to March 1812. Two of the earthquakes exceeded 8.0 on the Richter scale.

At that time, the great Shawnee leader Tecumseh (his name just happened to mean “Shooting Star”) was bringing together various tribes in a confederacy to fight back against the United States for seizing Native American land. As Tecumseh was meeting with other tribal leaders just 80 kilometers (50 mi) from the epicenter, the first quake (magnitude 8.1) hit the New Madrid, Missouri area.

As for Napoleon, he apparently embraced the comet as a sure sign of the justness of his reign, but it came in the years when he would embark on his worst military decision, the invasion of Russia. In fact, a total of three comets spanned the time between Napoleon’s invasion of Russia and his retreat.

3The Comet Of 1472

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In 1472, Leonardo da Vinci was at the height of his profession and Columbus was still 20 years away from discovering the New World. The year also marked the appearance of one of the great comets of the tail end of the Middle Ages.

Scientific observations of comets were in their infancy in 1472 when the comet appeared. Scientists of the day tried to determine its distance from Earth, the size, length, and direction of the comet’s tail, and the size of its nucleus. Their measurements and calculations left much to be desired, but still, this was cutting-edge science for the time. After all, the telescope would not appear for more than another 100 years.

One of the early astronomers who studied the comet of 1472 was a German mathematician named Johannes Regiomontanus. Not only did he study the comet, he also wrote down what he observed. The comet had come along at just the right time for Regiomontanus. The printing revolution was just taking off all over Europe, and Regiomontanus’s notes became De Cometis, one of the first astronomy books ever published.

Regiomontanus wasn’t the only one watching the comet. An Italian philosopher and physician named Angelo Cato de Supino claimed that the comet was as bright as the full Moon and had a tail over 30 degrees long. The comet was also being studied by the Koreans and the Chinese. The Chinese described it as a “broom star” and recorded that it “even appeared at midday.” The comet would be visible for 59 days and would ultimately reach -3 magnitude in brightness.

2Great Comet Of 1618

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Almost 150 years after the appearance of the Great Comet of 1472, Europe was enthralled with everything that could be observed, studied, recorded, and analyzed. But not everyone was getting with the times. In Prague, Protestants were tossing Catholic noblemen out of windows and triggering the Thirty Years’ War. But while all this was happening, Johannes Kepler was discovering the third law of planetary motion. Nobody paid much attention to what Kepler was up to, including the Catholic Church (fortunately for Kepler). But everyone noticed the comet that graced the sky in 1618.

Known as “the Angry Star” because of its reddish color and very long, menacing tail, the Great Comet of 1618 was visible for seven weeks, which was plenty of time for 17th-century Europeans to get excited about this visitor from beyond. One person who certainly got excited about the comet was Galileo, who saw this as a perfect time to refute Aristotle’s claim that comets were “fiery objects.” He claimed that comets were not like planets with regular circular orbits (wrong), and that comets were not even real objects—they were just appearances (wrong and wrong again). Even Galileo wasn’t right all the time.

But what really caught everyone’s attention was that in England, King James I had taken notice of the comet, and he even penned a poem about it. In his own kingly manner of prose, his Majesty told his subjects to calm down, because it was only a comet. Even if God Almighty sent the comet, he reasoned, your typical Englishmen shouldn’t make too much of it, and should “keep his rash imaginations till he sleep.”

1Comet Donati

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Comet Donati has two major distinctions that make it stand out in history. First, it is also known as “Lincoln’s Comet” because it was seen by the soon-to-be US president. When Lincoln observed Comet Donati in 1858, he was just a young Senate candidate from Illinois. Lincoln was said to have “greatly admired this visitor” and spent a considerable amount of time watching the comet in the night sky. Second, and of even more historical significance, Comet Donati has the distinction of being the first comet ever photographed.

In 1839, photography was invented by Louis-Jacques-Mande Daguerre, and astronomers quickly realized the potential applications of photography to their science. It didn’t take astronomers long to start snapping pictures of everything in the sky. The first successful daguerreotype of the Moon was made in 1840. By 1858, when Comet Donati became visible, the daguerreotype process was being improved with the wet collodion method. George Bond, an astronomer at Harvard, used a telescope and the collodion photography method to record the first-ever image of a comet. It wasn’t much to look at, but there it was. History had been made.

Besides these two historically important distinctions, Comet Donati was also a spectacular comet to observe. The night sky of the 1800s was not yet obscured by the modern curse of light pollution. People around the world, especially in the Northern Hemisphere, were in awe of the many spectacular comets that came along in the 1800s. It must have been marvelous to observe so many great comets in such a short period of time, under such perfect, dark skies.

Read more: http://listverse.com/2014/03/31/10-lesser-know-historic-comets/

Top 10 Cool Facts about Space

There is still so little known about outer space by modern science, but of that little we do know, there are some extraordinarily amazing things. This is a list of the top 10 cool facts about Space.

10. Lightweight

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Fact: If you put Saturn in water it would float

The density of Saturn is so low that if you were to put it in a giant glass of water it would float. The actual density of Saturn is 0.687 g/cm3 while the density of water is 0.998 g/cm3. At the equator Saturn has a radius of 60,268 ± 4 km – which means you would need an extremely large glass of water to test this out.

9. Constantly Moving

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Fact: We are moving through space at the rate of 530km a second

Our Galaxy – the Milky Way is spinning at a rate of 225 kilometers per second. In addition, the galaxy is travelling through space at the rate of 305 kilometers per second. This means that we are traveling at a total speed of 530 kilometers (330 miles) per second. That means that in one minute you are about 19 thousand kilometers away from where you were. Scientists do not all agree on the speed with which the Milky Way is travelling – estimates range from 130 – 1,000 km/s. It should be said that Einstein’s theory of relativity, the velocity of any object through space is not meaningful.

8. Farewell old friend!

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Fact: The moon is drifting away from Earth

Every year the moon moves about 3.8cm further away from the Earth. This is caused by tidal effects. Consequently, the earth is slowing in rotation by about 0.002 seconds per day per century. Scientists do not know how the moon was created, but the generally accepted theory suggests that a large Mars sized object hit the earth causing the Moon to splinter off.

7. Ancient Light

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Fact: The light hitting the earth right now is 30 thousand years old

The energy in the sunlight we see today started out in the core of the Sun 30,000 years ago – it spent most of this time passing through the dense atoms that make the sun and just 8 minutes to reach us once it had left the Sun! The temperature at the core of the sun is 13,600,000 kelvins. All of the energy produced by fusion in the core must travel through many successive layers to the solar photosphere before it escapes into space as sunlight or kinetic energy of particles.

6. Solar Diet

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Fact: The Sun loses up to a billion kilograms a second due to solar winds

Solar winds are charged particles that are ejected from the upper surface of the sun due to the high temperature of the corona and the high kinetic energy particles gain through a process that is not well understood at this time. Also, did you know that 1 pinhead of the sun’s energy is enough to kill a person at a distance of 160 kilometers? [Sourced from Planet Science]

5. The Big Dipper is not a constellation

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Fact: The Big Dipper is not a constellation, it is an asterism

Many people consider the big dipper to be a constellation but, in fact, it is an asterism. An asterism is a pattern of stars in the sky which is not one of the official 88 constellations; they are also composed of stars which are not physically related to each other and can be vast distances apart. An asterism can be composed of stars from one or more constellations – in the case of the Big Dipper, it is composed entirely of the seven brightest stars in the Ursa Major (Great Bear) constellation.

4. George’s Star

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Fact: Uranus was originally called George’s Star

When Sir William Herschel discovered Uranus in 1781, he was given the honor of naming it. He chose to name it Georgium Sidus (George’s Star) after his new patron, King George III (Mad King George). This is what he said:

In the fabulous ages of ancient times the appellations of Mercury, Venus, Mars, Jupiter and Saturn were given to the Planets, as being the names of their principal heroes and divinities. In the present more philosophical era it would hardly be allowable to have recourse to the same method and call it Juno, Pallas, Apollo or Minerva, for a name to our new heavenly body. The first consideration of any particular event, or remarkable incident, seems to be its chronology: if in any future age it should be asked, when this last-found Planet was discovered? It would be a very satisfactory answer to say, ‘In the reign of King George the Third.’

Uranus was also the first planet to be discovered with the use of a telescope.

3. Extra Moons

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Fact: Earth has at least 4 moons

Okay – that is not actually true – but it is very close. In 1986, Duncan Waldron discovered a asteroid (5km across) that is in an elliptic orbit around the sun with a period of revolution virtually identical to that of Earth. For this reason the planetoid and earth appear to be following each other. The periodic planetoid is named Cruithne (pronounced krin-y?) after an ancient group of Scottish people (also known as the Picts). Because of its unusual relationship with Earth, it is sometimes referred to as Earth’s second moon. Cruithne, is fainter than Pluto and would require at least a 12.5 inch reflecting telescope to attempt to be seen. Since its discovery, at least three other similar asteroids have been discovered. These types of objects are also found in similar relationships to other planets in our Solar System. In the image above (courtesy of Paul Wiegert), the earth is the blue circle with a cross in it, and Cruithne’s orbit is shown in yellow.

2. Sunspot Music


Fact: Sunspot activity may be the primary reason for the beautiful sound of Stradivarius violins

Antonio Stradivari is considered to be the greatest violin maker ever. He lived in Italy in the 17th and 18th centuries. Scientists have been unable to work out what it is about his violins that makes them so incredible, but they do know that the timber used to make them is a very important contributing factor. From the 1500s to 1800s, the earth underwent a little ice age mostly due to increased volcanic activity and decreased solar activity (this is called the Maunder Minimum). As a result of this cooling, the types of trees that Stradivari used for his violins were particularly hard (due to slow growth). Hard timber is especially good when making violins. It is very probable that had Stradivari lived in a different age, his violins would not be prized as they are today. This picture above is made of three overlapping photos. It shows the rings in the spruce tree used to make the most famous Stradivarius violin, the “Messiah.” The first row of numbers gives the width of each ring in millimeters (one mm is about the thickness of a fingernail). The bottom row gives the years in which each ring grew.

1. Cold Welding

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Fact: If two pieces of metal touch in space, they become permanently stuck together

This may sound unbelievable, but it is true. Two pieces of metal without any coating on them will form in to one piece in the vacuum of space. This doesn’t happen on earth because the atmosphere puts a layer of oxidized material between the surfaces. This might seem like it would be a big problem on the space station but as most tools used there have come from earth, they are already coated with material. In fact, the only evidence of this seen so far has been in experiments designed to provoke the reaction. This process is called cold welding. For those who still don’t believe it, here is the Wikipedia article on Cold Welding.

Read more: http://listverse.com/2007/11/13/top-10-cool-facts-about-space/

10 Things That Happen To An Exposed Human In Space

We’ve all seen it in sci-fi movies: Someone gets sucked out of a spaceship and thrown into the emptiness of space. Not surprisingly, many movies get it wrong. But the reality of a human exposed to the vacuum of space may be weirder and more bizarre than you ever imagined.

10 The Vacuum Of Space


First things first—if the exterior of your spaceship is compromised (punctured by a whizzing asteroid perhaps) the interior will rapidly depressurize, and you will be sucked out into the vacuum of space.

The ship would initially be pressurized in order to mimic earth’s atmosphere and maintain a proper, livable environment. But once the ship is damaged, the air inside will rapidly expand outward, creating a vacuum and violently pulling everything out with it—including you. If you’re lucky enough to not be killed by flying debris during the ordeal, you’ll still find yourself in a pretty grim situation: you’ll be left to fend for yourself, floating hopelessly in the abyss of space.

9 Extreme Swelling


Remember Veruca Salt from Willy Wonka and the Chocolate Factory who puffed up like a giant blueberry? The effects of space on the human body would be quite similar. Without the presence of Earth’s atmospheric pressure, the water that makes up 70 percent of our bodies doesn’t remain in its liquid state and expands until it forms water vapor. This would result in severe internal swelling throughout the body. In fact, a person would balloon out to approximately twice their normal size. The formation of the vapor wouldn’t be enough to burst the skin, but it’s safe to say you would experience some serious discomfort.

8 Exposure To Sunlight


A day at the beach can be ruined by a painful sunburn—especially if you forget your sunblock. Now imagine being exposed to the power of the sun without our ozone layer filtering out the most harmful ultraviolet rays. The effects would be devastating to the human body. A person floating in space would be horribly burned over any portion of exposed skin. In addition, looking directly into the sun would fry your light-sensitive retinas and render you blind. And even if you did survive, your likelihood of contracting skin cancer would increase dramatically.

7 Suffocation By Hypoxia


When exposed to the vacuum of space, a person will be totally deprived of oxygen, but not in the way you might think. The condition is known as hypoxia: Without earth-like pressure, the oxygen in your bloodstream will begin to reverse-dissolve and escape from your blood. This will render your cardiovascular system useless, and no oxygen will be delivered to your muscles or vital organs. The fact that you are no longer able to breathe in any new oxygen just exacerbates the problem. In addition, the suffocating effect would begin to turn your skin blue. A person can last approximately 10 seconds in this condition before they black out.

6 Rapid Cooling


On a hot day, our bodies produce sweat to cool down. As the sweat evaporates from the surface of our skin, it uses up heat energy and causes a cooling effect. But this effect is greatly exaggerated in outer space. Normally, the humidity in the air inhibits the cooling effect quite a bit because it’s harder for sweat to evaporate into air that’s already saturated with water. But in the dark emptiness of space, there is no humidity. This allows for the accelerated evaporative cooling of any exposed bodily fluids. Your watery eyes, mouth, and respiratory tract will freeze over as a result.

5 Decompression Sickness


As we’ve already seen, the low pressure of space prevents oxygen from remaining dissolved in your blood. This vacuum-like environment does the same for other gasses, like nitrogen. This causes tiny nitrogen bubbles to form all throughout your circulatory system (which is the literal definition of the bends). One side effect these bubbles have is extreme joint pain, but far worse are the effects the bubbles have when they create blockages in your veins and arteries. Bubbles in your brain can cause stroke and seizures. A bubble in your heart can cause sudden heart failure and death.

4 No Blood Pressure


As you can tell by now, space has horrible effects on the human body. Both internally and externally, you are stretched, ballooned, and otherwise contorted. As a result, your misshapen body will struggle to maintain a normal blood pressure. For example, a person can easily generate enough force to drink soda through a normally sized straw. But what if the straw’s diameter was 10 times as large? Similarly, your heart would not be capable of pumping blood through your enlarged veins. Your blood pressure would effectively drop to zero and you would die.

3 Explosive Decompression


One fatal mistake you could make as you’re sucked out of your spaceship would be taking one final, deep breath. You might think the extra air would help you stay alive for another minute or so, but the actual result would be quite the opposite. Holding that air in your lungs in the vacuum of space would result in explosive decompression—of your lungs. Imagine that for a second.

The air would expand violently in the low-pressure environment and cause your lungs to burst like balloons. If you ever find yourself in such a situation, you would be wise to exhale as much as possible to avoid this explosive trauma.

2 Boiling Blood


The lower the pressure is in an environment, the lower the boiling point will be for any liquid in that same environment. This is because when there’s less pressure, it’s easier for the molecules to move around, so it takes less heat energy to transform the packed-in molecules of a liquid to a less-dense gas.

This is why water boils more easily at higher altitudes. In space, the boiling point of your blood could realistically drop down until it’s the same as your own body temperature—at which point your blood would begin to boil. The temperature of your blood would still be normal, but in the vacuum of space that might be all it needs to boil.

1 Cellular Mutation


Even if you somehow managed to survive space exposure, you still wouldn’t be out of the woods. In addition to these other issues, the blackness of space also contains many invisible dangers. During the brief time that you were exposed, you would be bombarded with a whole host of dangerous sub-atomic particles. This includes gamma rays, energized protons, and x-rays. These particles are so small that they interact with you on a cellular level and actually alter you DNA. But this would not result in superpowers as some comic books might suggest. Instead, you would almost certainly die of radiation poisoning or cancer years later.

Read more: http://listverse.com/2013/07/06/10-things-that-happen-to-an-exposed-human-in-space/