In late February, astronomers announced the discovery of Trappist-1, a potentially habitable planetary system. The planets were Earth-sized and rocky, and there were seven of them. Now that the media frenzy has calmed down, Seeker has everything you need to know about Trappist-1.
The seven exoplanets are "Earth-sized" and they orbit really close to their star, Trappist-1. The star is less than a tenth the size of The Sun, and colder. Several of the earth-sized planets are in the habitable zone; meaning they orbit the perfect distance to get surface temperatures that could support liquid water, though that doesn't mean they have any. Some scientists got carried away, calling Trappist-1 our "sister solar system," and some of your twitter friends were probably ready to move there. Again, all very exciting.
Then, to add to the hype, another study of the Trappist-1's planets found they're so close together, that if they were to harbor life (and they didn't say they would) any meteor impact on one could throw life on to their neighbors, like blood spatter. I should mention, they hedged their bets on this, writing that the vacuum of space would make it really hard for life to move from one to the other, but if there was life on one, there'd likely be life on more than one.
But, now, as is their job, a group of scientists pointed the Hubble at Trappist and found it might not be as habitable as it appears to be.
Seeker: 'Habitable' Exoplanets Might Not Be Very Earth-Like After All
ScienceAlert: Astronomers Aren't Sure if TRAPPIST-1's Planets Are Habitable After All
NASA: NASA Telescope Reveals Largest Batch of Earth-Size, Habitable-Zone Planets Around Single Star