10 Unexplained Space Mysteries

No. 9 - A Possible Probing

A space object of unknown origin called 1991 VG is floating around the heavens above. Its Earth-like orbit and fast fluctuations in brightness suggest that the 30-foot entity isn't simply an asteroid or remnant from the space age, as was initially assumed. About 20 years ago, the object made a close approach to Earth that some believe was indicative of a controlled encounter rather than a random encounter. Is 1991 VG an alien probe as these people have suggested? We'll have to wait about five years for even a chance at the answer. The object is currently too far from our planet to investigate. However, if the mysterious body stays on the same path, it should approach Earth again in 2017. Can't wait!

No. 8 - Maybe Women Are From Venus

Once Earth-like, Venus is now a blistering planet filled with noxious gases. Still, scientists say there's a spot about 30 miles above the planet's surface where the temperature, pressure and chemicals are extremely similar to our own atmosphere, and life could theoretically exist there. Floating organisms resembling bacteria could thrive in such an environment, as they do in the clouds above Earth. If there is in fact life over Venus, we haven't found any hard evidence proving so just yet. Missions to gain samples using a giant, flying balloon have been proposed, but never undertaken.

No. 7 - Mind the Gap

In 2007, a group of American scientists found a massive hole spanning one billion light years in the Eridanus constellation. (One light year is about six trillion miles.) The area lacked signs of cosmic matter like stars, planets, galaxies or clouds of dust. Researchers couldn't even find dark matter. And there were no indications of black holes that could have sucked up the matter that used to be there. Though other holes in the universe have been found before, they were just 1/1,000th the size of this supervoid. How this giant gap came to be and why it's so colossal is totally unknown. We're hoping the hole turns out to be a portal to Narnia.

No. 6 - The Lunar Family Tree

Most men of science agree that Earth's moon probably formed from a chunk of the planet that was knocked off by some ancient collision. Nevertheless, this hypothesis has one serious problem: whatever hit Earth would have left a residue with distinguishing characteristics. Hard as they try, scientists cannot find any remnants from this rather large impact. Right now, the origin of the moon is all moonshine.

No. 5 - Supernova or Supernatural?

An Old English manuscript that details the history of Anglo-Saxon life notes that a mysterious red crucifix appeared in the skies over Britain in 774 A.D. While scientists have long posited that the event was a supernova, such an occurrence would have created a large influx of radiation that would still be evident in Earth's geology. After centuries of searching, the only inkling of environmental proof was found just last month, when Japanese scientists found tree rings from 774 that indicate a spike in C-14. While the discovery may be linked to a supernova, and perhaps the one that caused the red crucifix, more evidence is needed before real conclusions can be drawn.

No. 4 - Mercury's Collision Course

Mercury is notoriously tough to study thanks to its neighbor, the scorching, blinding sun. In addition to not knowing where the planet's atmosphere or magnetic fields originated, we have no idea why Mercury's elongated orbit around the sun is constantly growing more and more oval-shaped. Scientists predict that the planet will eventually crash into either Venus or the sun. Mercury's changing path could also alter the gravitational fields in our solar system, disrupting Earth's orbit along with the other inner planets, causing complete and utter chaos.

No. 3 - E.T. Phoning From Home?

Several times a week in the late 1970s, Ohio State University Professor Jerry Ehman would receive computer printouts reporting deep-space sounds captured by the university's observatory. In the summer of 1977, he saw six symbols that indicated a 72-second signal 30 times louder than any previous sound from space. He circled the sequence and wrote "Wow!" "The Wow! Signal," as the noise was called thereafter, had a frequency and shape that suggested intentionality. However, while the area from which the noise came could be determined, scientists were unable to pinpoint an actual source. In the years since, a number of logical explanations for the signal, like a satellite transmission, military signal or broadcast beam, have been ruled out. While some still think the sound was extraterrestrials attempting contact, critics are quick to point out that there hasn't been a repeat transmission since. So either something else made the sound, or aliens are quitters.

No. 2 - Not a Passing Storm

Perceived by the first telescopes in the 15th century, an enormous, high-pressure storm has been pounding Jupiter for no less than 400 years. Big enough to fit three Earths in its span, much about the Great Red Spot, including what causes its scarlet hue and why it has persisted for so long, is unknown. To add to the confusion, recent research has suggested that the spot is slowly shrinking. While the storm looked like a long sausage a century ago, it's much more circular on current satellite images. Scientists have numerous theories regarding the spot's doggedness, color and shape, but they are mere speculation. Also, every probe sent to Jupiter for more info has been crushed by the planet's lethal atmosphere. So that's no help.