The Milky Way panorama by European Southern Observatory

Steinn Sigurðsson recently spent a weekend considering exoplanets and extraterrestrials at the Second SETI Conference in California.  He writes, “It is important to remember that while science and discovery is important, it is not the ontological basis for space exploration. Space is, ultimately, about existential motivations.”  In other words, we wouldn’t mind finding a friend, or a new Earth to colonize when this one gets fried by the sun.  As Kepler continues to increase the number of known planets in the galaxy, it may only be a matter of time.  And exoplanetary science is in its infancy.

On Starts With a Bang, Ethan Siegel writes “the Universe is an extremely diverse place, where every combination of planets and solar systems we can think of very likely exist.” The star system Kepler-36, for example, features two planets in such close orbits that every 97 days, one rises like a massive moon in the sky of the other. But that’s still not near enough for Ethan, who wants to escape Earth’s gravity well without rocket fuel. He could float over to Neptune if it were 1,000 miles away—but the Earth would also be torn apart.  That’s called a minor detail.