They announced the discovery of some seemingly Earth-like planets outside of our solar system, a group of rocky globes they're calling 'TRAPPIST-1.' Watch: pic.twitter.com/cBBerkelU1 — NASA (@NASA) February 25, 2017I called up one of NASA's exoplanet experts, Aki Roberge, to help us break down the find. But it's a smaller star, it's closer to us, and it's got more planets – really tightly packed. Just look at our solar system: we have three rocky planets – about the size of the TRAPPIST-1 planets. Q: What's the big deal about 'rocky' planets?

Source: Forbes February 26, 2017 17:49 UTC