Goldilocks Planets: This One’s Just Right

Tuesday, May 15th, 2012

As any Star Trek fan can attest, traveling to faraway planets has long been a central theme in science fiction. But if distant planets inspire us and allow us to imagine other civilizations, the reality of actually visiting a faraway planet is decidedly more daunting. With a surface temperature at 420 degrees Celsius, Venus, for example, wouldn’t exactly be a fun place to explore for a day.

If humans do ever manage to travel to other planets, we’ve found what might be a nice place to make our first stop. In 2011, NASA made news by announcing that the Kepler Space Telescope had found the first planet, Kepler 22b, that could possibly sustain life. Dubbed a “Goldilocks planet” because it’s not too hot and not too cold for life, Kepler 22b is just the right distance from the star it orbits to maintain liquid water on its surface. The planet’s estimated surface temperature of 72 degrees Fahrenheit (22 degrees Celsius) makes it possible that it’s a lot more like Southern California than, say, the barren landscape of Mars.

In other words, if  we could only get there, humans may have found a possible haven in Kepler 22b — that is, if things don’t end up so well here on Earth. 

Considering the vastness of space, it was perhaps only a matter of time until we found a Goldilocks planet. Kepler 22b merely verified a widely-held assumption that with so many stars in the universe, it’s inevitable that some of them are orbited by planets with similar conditions to Earth. And, sure enough, recent findings have shown that Kepler 22b might not be so unique after all. In March, a team of international researchers led by Dr Xavier Bonfils, from Grenoble University in France, announced that billions of Goldilocks planets might be orbiting the billions of red dwarf stars in our galaxy.

Smaller and cooler than the sun, red dwarfs are all around us, making up some 80% of the 200-400 billion stars in our galaxy.  According to the paper Bonfil’s team published in the journal of Astronomy & Astrophysics, 40% of red dwarfs could have a planet that falls in the Goldilocks zone. In other words, astonishing though it sounds, there could be billions of potentially habitable planets in the Milky Way alone.

Among those billions of planets, the researchers have already identified nine ‘Super-Earths’, which have masses between one and 10 times that of Earth.

Of course, before we start packing, there’s some additional info to keep in mind.  The Goldilocks planets orbiting red dwarfs are closer to their respective stars than the Earth is to the sun. And for this reason, they are susceptible to stellar eruptions or flares that could cover them  in ultraviolet radiation and X-rays.

Hmm. Maybe we should stick around Earth just a little bit longer.

by Jason Taetsch

Jason Taetsch is a freelance content writer with experience in tech writing, blogs, travel writing, pop culture and a range of promotional materials. Jason blogs via Contently.com.