Astronomers have never seen anything like this before: Seven Earth-size alien worlds orbit the same tiny, dim star, and all of them may be capable of supporting life as we know it, a new study reports.
“Looking for life elsewhere, this system is probably our best bet as of today,” study co-author Brice-Olivier Demory, a professor at the Center for Space and Habitability at the University of Bern in Switzerland, said in a statement.
The exoplanets circle the star TRAPPIST-1, which lies just 39 light-years from Earth — a mere stone’s throw in the cosmic scheme of things. So speculation about the alien worlds’ life-hosting potential should soon be informed by hard data, study team members said.
“We can expect that, within a few years, we will know a lot more about these planets, and with hope, if there is life there, [we will know] within a decade,” co-author Amaury Triaud, of the Institute of Astronomy at the University of Cambridge in England, told reporters on Tuesday (Feb. 21).
A bizarre alien system
TRAPPIST-1 is an ultracool dwarf star that’s only slightly larger than the planet Jupiter and about 2,000 times dimmer than the sun.
The research team, led by Michaël Gillon of the University of Liège in Belgium, originally studied the star using the TRAnsiting Planets and PlanetesImals Small Telescope (TRAPPIST), an instrument at the La Silla Observatory in Chile. (This explains the star’s common name; the object is also known as 2MASS J23062928-0502285.)
TRAPPIST spotted regular dimming events, which the team interpreted as evidence of three different planets crossing the face of, or transiting, the star. In May 2016, Gillon and his colleagues announced the existence of these three alien worlds, called TRAPPIST-1b, TRAPPIST-1c and TRAPPIST-1d. All three, the team reported, are roughly the size of Earth and may be capable of supporting life.