Alien Planets & Eyeball Earths: The Search for Hab
Find out, in 1080p, where to look for Extraterrestrial Life. What planets are likely to have the right conditions? And what makes Earth special? So far, in this age of planet hunting, we’ve yet to find anything like our solar system… with rocky inner planets in neat circular orbits, and evenly spaced gas giants on the periphery.
Instead, astronomers have glimpsed a diverse planetary zoo, with giant planets in wide orbits around their parent stars, others that swing in so close they leave a comet-like tail, or molten rocky worlds emblazoned with oceans of lava. These finds have added new complexity to theories of how solar systems emerge in the birth of a star.
As dust and gas swirl into the newborn star, they form a proto-planetary disk. Within this Frisbee-like structure, gravity sculpts planetary bodies that grow in size, sweeping up smaller bodies that form around them. Current theory holds that giant planets, forming on the periphery, commonly migrate into the inner solar system. This confirms the observation of so-called hot Jupiters orbiting perilously close to their parent stars.
But these giants may clear out smaller rocky planets that form close to the star, creating a planetary desert… just where you’d hope to find life. Does that make the search for another Earth a wild goose chase? To find out, a group of planet hunters, using the Keck Telescope in Hawaii, examined a sample of 166 sun-like stars within 80 light years of Earth.
To their surprise, they found that as many as a quarter of all sun-like stars should have planets roughly the size of Earth. Now enter the Kepler Space Telescope, launched in March 2009 on a mission to find Earth-like planets.
Over a four-month period in 2009, it observed the light of over 150,000 stars, within 3000 light years of Earth. The data showed that at least in one case, the planetary desert is not so barren.
The star Kepler 11 is a yellow dwarf similar to our sun. It has at least five planets close enough