Artistic Impression: The Surface of TRAPPIST-1f.

If you could stand on the surface of the newly discovered Earth-sized exoplanet TRAPPIST-1f, what would you see? Presently, no Earthling knows for sure, but the featured illustration depicts a reasoned guess based on observational data taken by NASA 's Sun-orbiting Spitzer Space Telescope . In 2017, four more Earth-sized planets were found by Spitzer, including TRAPPIST-1f , in addition to three discovered in 2015 from the ground. From the planet's surface , near the mild terminator between night and day, you might see water, ice, and rock on the ground, while water-based clouds might hover above. Past the clouds, the small central star TRAPPIST-1 would appear more red than our Sun , but angularly larger due to the close orbit. With seven known Earth-sized planets -- many of which pass near each other -- the TRAPPIST-1 system is not only a candidate to have life, but intercommunicating life -- although a preliminary search has found no obvious transmissions .