The question of whether or not we are alone in the universe — certainly one of the most profound which has ever perplexed mankind — may have been answered.
A number of news sources are reporting that a team of European astronomers have discovered a planet located about twenty light years away from Earth, with potentially life sustaining qualities remarkably similar to our own planet. The planet, currently being called Gliese 581c is named for its close proximity to its "sun" — the red dwarf star Gliese 581. It is roughly one and a half times the size of earth, measuring about 12,000 miles across compared to our own 8,000.
Gliese 581c's surface is also believed to be solid. Like Earth, it is most likely covered with both rock and water, rather than an ice-based or gaseous surface. It has a mass five times the size of earth, giving it enough gravity to maintain a stable atmosphere. The planet is also most importantly believed to maintain temperatures between 32 and 104 degrees. These properties — among the most basic elements necessary to sustain life as we know it — have led to some reports labeling Gliese 581c as the "New Earth".
If life does indeed exist on Gliese 581c however, its inhabitants would have to deal with a few drawbacks. Parent sun Gliese 581 is only about one third the size of our own, and is 50 times cooler. However, it is also considerably closer, orbiting at about six million miles away (compared to our larger sun at 93 million miles away). This would make for a spectacular Glieseian sunset dominated by the huge red star appearing some twenty times the size of our sun. However it would also mean greater solar radiation and higher geologic instability due to the gravitational tides from the nearby sun.
Still, you can't help but marvel at the possibilities. While there have been many exciting discoveries made within our own solar system over the past few decades — such as bacteria on Mars and possible water on the moons of Jupiter and Saturn — this is the first time a planet so similar to Earth has been discovered outside our own immediate neighborhood. It's relatively close proximity of 120 trillion miles — or about 20 light years away — also gives projects like SETI (The Search for Extraterrestrial Intelligence) a prime target at which to point its equipment searching for alien radio signals.
"On the treasure map of the Universe, one would be tempted to mark this planet with an X," said Xavier Delfosse, one of the scientists who discovered the planet. The discovery of the first planet outside our solar system so much like Earth, with so many of the same life sustaining properties, at the very least both provokes a sense of wonder and the awe of possibility.