Astronomers discover nearby super-Earths that could "potentially host life"
Scientists may be one step closer to figuring out if we're alone in the universe. Astronomers recently discovered several nearby exoplanets that they say could "potentially host life," orbiting the brightest red dwarf star in the sky.
According to a study published Thursday in the journal Science, a planet-hunting team of astronomers have found two super-Earths orbiting the red dwarf star Gliese 887. The host star is just 11 light years from Earth — making us practically neighbors.
The team monitored the system using the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph at the European Southern Observatory in Chile and analyzed nearly two decades of archival data on the star. Using a technique called the "Doppler wobble," the astronomers found the planets to have orbits of just 9.3 and 21.8 days — faster even than Mercury.
Super-Earths are planets with masses higher than Earth's but lower than those of ice giants like Uranus and Neptune. The exoplanets, or planets located outside of our solar system, have been dubbed Gliese 887b and Gliese 887c.
The planets are located near their star's habitable zone — an area where liquid water could exist. However, scientists said the temperature of the later planet is about 70 degrees Celsius, or 158 degrees Fahrenheit.
They also believe the planets could be rocky, like Earth and Mars.
Unlike other red dwarfs, this star has very few starspots and is much less active — meaning the newly-discovered planets have a better chance of retaining their atmosphere, making conditions for life more plausible. More active stars are prone to dangerous flares, which could easily destroy a planet's atmosphere.
"It's the best star in close proximity to the sun to understand whether its planets have atmospheres and whether they have life," lead author Dr. Sandra Jeffers told the journal Nature. "GJ 887 is exciting because the central star is so quiet. That's the exceptional part."
Jeffers said astronomers have been looking for signals in this star for 20 years.
According to the study, researchers also found evidence of a possible third planet further away from the host star. It has an orbit of about 50 days and may have a surface temperature more suitable to liquid water, and therefore life.
The system is now a prime target for the James Webb Space Telescope, the successor to the Hubble Telescope, which is set to launch next year.
"These planets will provide the best possibilities for more detailed studies, including the search for life outside our Solar System," Jeffers said in a news release.