Hello again! Boy, I tell ya, it’s good to be back in the swing of things. You know what they say about absence making the heart grow fonder? Well, they also say a few things about being addicted to your devices! But either way, I’m happy to be back in civilization and able to communicate with my friends and colleagues who are, unfortunately, only reachable electronically.

And I’m even happier that people have had a creative outburst while I was away. I miss being able to take part in brainstorming sessions and coming up with new ideas with people. So I was pretty pleased when I came home and found my inbox so crammed full of emails and comments from my writer friends. And, like a plant that’s been deprived of water, their thoughts set my mind aflame with new ideas!

For one, I realized I had yet to discuss NASA’s top 5 Exploplanets in any real detail. Not long ago, it was announced that the planet Gliese 581 g, which is roughly 20 light years from our Solar System, is the most Earth-like planet in this region of the Galaxy, and hence, the most likely candidate for settlement someday. However, this news came as part of a larger story about all the planets, Earth-like or otherwise, that NASA has been confirming the existence of in recent years. Guess I was too busy focusing on how this effecting my writer’s group to expand on how cool these discoveries really are 😉

The table above shows the top five contenders, grouped according to how similar they are to Earth in terms of gravity, atmosphere, distance from their star, and ability to support life. Gliese 581 g, the fourth planet from the Gliese 581 star, ranks as number one with a 92 percent comparison match. Being roughly the same size as Earth, though boasting significantly more mass, it is also thought to have roughly the same gravitational pull. In addition, the astronomer who was intrinsic in it’s discovery, Steven Vogt, indicated that it is a prime candidate for extra-terrestrial life.

The second candidate, at 85%, is Gliese 667C c, a planet which orbits a red dwarf roughly 22 light-years away. It is so named because it’s parent star is part of a triple star system, or a trinary. Since c is estimated to be at least 4.5 times as massive as Earth, it has the honor of being designated a “Super-Earth”, and no doubt would have enough gravity to make even a world-class athlete feel overwrought from the simple task of walking.

Third is Kepler-22 b, an exoplanet which was spotted by NASA’s planet-hunting Kepler space telescope in 2009. An 81% match to Earth, this world is another “Super-Earth” which is speculated to have an atmosphere and climate which could be hospitable to Earth creatures. Unfortunately, this bad boy is over 600 light years away, making it a pretty poor candidate for settlement anytime soon.

Fourth up is HD 85512b, another super-Earth which orbits the orange dwarf Gliese 370, which is roughly 35 light-years away. At a relatively reasonable distance, and a 77% match to Earth, this planet could be a suitable candidate for colonization one day. NASA already estimates that its average surface temperature and presence within the star’s “Habitable Zone” would be within tolerable limits. Hopefully the gravity is the same!

And coming in at fifth place is the second planet to come to us from the Gliese 581 system, the fifth planet known as Gliese 581 d. As the above table shows, g and d are both within the systems Habitable Zone and could be made to support human populations, provided certain requirements (i.e. the existence of water, suitable temperatures and gravity) were met. When it was first discovered in 2007, it was dismissed as being “too cold” to support life. However, subsequent atmospheric modelling studies suggest that it could be habitable provided its atmosphere is capable of generating a Greenhouse Effect, as Earth’s is.

Many question how and why the discovery of exoplanets will benefit humanity. As one of my friends (hi Rami!) asked me recently, what good is it to colonize worlds do us if our problems remain? I argued that it would ensure our survival, but quickly realized that I’d need to make a better case if I was going to prove that point. As a curve-ball, I asked him to consider the possibility that maybe Earth itself, as we’ve made her in the past 15,000 years, could be the problem…

Naturally, that statement requires clarification. But that’s something for another time. Right now, all I am hoping for is that the discovery of habitable planets within humanity’s reach will mean either the possibility of extra-terrestrial life, or the option of planting the seed of humanity in a distant solar system. The implications of either would be mind-blowing, and I for one feel privileged to live in a time when such possibilities might be coming true!