Alien life may or may not exist, but we know now that there are far more earthlike planets out there than we previously imagined. Ravi Kopparapu, a researcher from Penn State who will be publishing his findings in an upcoming issue of Astrophysical Journal Letters, has recalculated the chances of finding earth-sized planets in our galaxy and discovered that they're about twice as common as we thought.
While previous estimates said that the nearest possible earth was about 14 light years away, Kopparapu's estimate placed the nearest habitable planet at about seven light years out and maybe even as close as 6.5 light years. "This is a good sign for detecting extraterrestrial life," he told New Scientist.
The recent discovery of Kepler 37b, the world's smallest planet outside our solar system, also offered new hope that there are plenty of smaller planets out there available for the development of life in our galaxy.
But is it really such a good sign?
If there are so many earthlike planets, and, if they are all teeming with life, then where the heck are they? The so-called Fermi Paradox was first posed in the twentieth century by Enrico Fermi, an Italian physicist known for his work on the first nuclear reactor. He ran some back-of-the-envelope calculations and suggested that, in a universe billions of years old, even if they could never travel anywhere near the speed of light, any aliens that developed before humans did would have long ago had the time to seed every possible habitable planet.
And, in fact, Charles Cockell, Director of the UK Centre for Astrobiology at the University of Edinburgh, is planning to give an address this week to the UK's prestigious Royal Society that makes the same argument. According to the Society, 800 planets outside of our solar system have already been found, and scientists need to set an agenda about how they will deal with the discovery of alien life.
Professor Cockell will argue that vacant habitats on earth almost never stay vacant for long. Life moves in quickly to exploit an empty space. "It is dangerous to assume life is common across the universe – it encourages people to think that not finding signs of life is a 'failure' when in fact it would tell us a lot about the origins of life," he has said.
It's a little frustrating, isn't it? Here it is, the 21st century, and we still don't have our jetpacks or our alien life.
[Photo Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)]