The quest for a twin Earth is heating up. Francois Fressin, of the Harvard-Smithsonian Center for Astrophysics (CfA), presented the new analysis of Kepler data that shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury.
Imagine a giant world like Jupiter, but more alien than any planet in our solar system. Instead of displaying gleaming clouds colored white and salmon, this world is darker than the blackest lump of coal. It glows only with a feeble red light like a stove's electric burner — the result of scorching heat from a sun just 3 million miles away.