How far is TRAPPIST-1 from Earth?
TRAPPIST-1 is approximately 40.66 light-years from Earth. It lies in the constellation Aquarius, five degrees south of the celestial equator.
Questions about TRAPPIST-1
Short answers, pulled from the story.
How many planets orbit TRAPPIST-1?
Seven confirmed planets orbit TRAPPIST-1, designated TRAPPIST-1b through 1h. A candidate eighth planet, TRAPPIST-1i, was identified in 2025 from James Webb Space Telescope transit data but has not yet been confirmed.
Which TRAPPIST-1 planet is most likely to be habitable?
TRAPPIST-1e is considered the most likely of the seven planets to harbor liquid water. It has a density similar to Earth's and is ranked by multiple climate models as the best candidate for retaining water across a wide range of atmospheric conditions.
Who discovered the TRAPPIST-1 planetary system?
The planetary system was discovered by a team led by Michaël Gillon, a Belgian astronomer at the University of Liege, during observations at La Silla Observatory in Chile in 2016. The underlying star was first identified by John Gizis and colleagues in June 1999 and published in 2000.
How old is TRAPPIST-1?
TRAPPIST-1 is estimated to be about 7.6 billion years old, making it older than the Solar System, which is approximately 4.5 billion years old. It is expected to continue fusing hydrogen for ten trillion years.
Why do TRAPPIST-1 planets have uncertain atmospheres?
TRAPPIST-1 produces frequent stellar flares, intense X-ray and ultraviolet radiation, and a stellar wind that may be one thousand times stronger than the Sun's wind at Earth's orbit. These forces can strip away planetary atmospheres over time, especially on the innermost planets. The James Webb Space Telescope has already ruled out an atmosphere around TRAPPIST-1b.