According to a recent report by NPR, astronomers have recently discovered seven earth-sized planets orbiting a nearby dwarf star. Collectively, the planetary system is being referred to as TRAPPIST-1. Several scientists are saying that the conditions provided by the solar system could be just right for liquid water, in which case its planets would have the potential to sustain life.
The reddish star, which is a member of the constellation Aquarius, is "ten times smaller" than our sun, according to Michaël Gillon, an astronomer at the University of Liège in Belgium. The seven planets that orbit it are about as close as Mercury is to our sun, but, because of the star's small size, it isn't hot enough to totally fry them. Although there are concerns about the level of ultraviolet radiation exposure, astronomers are hopeful that the planets' atmospheres aren't too damaged.
"If you were on the surface of one of these planets," says Gillon, you would see the other ones as we see the moon, or a bit smaller ... The view would be very impressive."
When scientists first began studying TRAPPIST-1 about a year ago, they observed up to three planets orbiting the single dwarf star and decided to pursue further research. Now, thanks to additional observations that were made using the Hubble Space Telescope, four more have been found. Upon completion of the next-gen James Webb Space Telescope in 2018, several additional in-depth atmosphere-based observations are planned.
The discovery of TRAPPIST-1 sets a new record for the most Earth-sized planets as well as the most potentially habitable planets ever discovered surrounding a single star. Until recently, however, astronomers weren't even looking for solar systems centered around dwarf stars, as they were previously thought to be too cold.
In addition to this game-changing discovery, scientists have been gathering piles of evidence that celestial bodies like these are common in our galaxy. According to Ignas Snellen at the University of Leiden in the Netherlands, TRAPPIST-1's discovery suggests that such worlds are "even more common than previously thought."