FROM THE EARTH TO TRAPPIST-1C: 2 ‘Nearby’ Exoplanets Confirmed to Be Rocky — and May Be Habitable.
Judging from the size and temperatures of the three planets around TRAPPIST-1, researchers previously suggested that regions on each world could be habitable — that is, have surfaces with just the right temperatures to harbor liquid water, a key ingredient of life as it is known on Earth. However, it was uncertain if these three planets were rocky worlds like Earth.
Now, TRAPPIST-1’s discoverers have found that the star’s two innermost worlds, TRAPPIST-1b and TRAPPIST-1c, are indeed primarily rocky planets.
The scientists made this new discovery by pointing NASA’s Hubble Space Telescope at TRAPPIST-1 to catch a rare event on May 4: a double transit, when two planets — in this case, TRAPPIST-1b and TRAPPIST-1c — pass in front of their star at nearly the same time.
The story also reports that “nearby” is still about 39 lightyears from Earth.