Scientists are on the hunt for exo-Earths, distant cousins of our planet that are just the right distance from their stars to harbor liquid water and other ingredients for life. But even with plenty of data and some educated guesses, no one will ever see what these faraway worlds look like, so we're left with the creative concepts of NASA artists.
A tiny world of molten rock, orbiting scorchingly close to its host star, is the smallest planet ever discovered outside our solar system, NASA announced today. And it's likely only the first in a parade of planet discoveries to be announced this spring by the Kepler Space Telescope team.
If it seems like a new extrasolar planet is discovered every week these days, that's because there is. In fact, the rate is actually faster than one per week – 70 have been discovered thus far this year alone, bringing the overall tally of confirmed exoplanets at 494. At that pace we very well might hit exoplanet number 500 before the end of this month.
A couple of math geeks recently calculated that the discovery of the first "habitable" exoplanet would be announced in May of next year -- but a few stargazers from UC Santa Cruz and their colleagues simply couldn't wait that long. In a paper published in the Astrophysical Journal, the astronomers report the discovery of what may be the first truly habitable earth-like exoplanet orbiting the nearby red dwarf star Gliese 581.