NASA scientists revealed on Wednesday, Feb. 22, the discovery of seven Earth-sized planets that orbit a nearby dwarf star in tight, fast ellipses. The location and characteristics of the exoplanets draw astronomers closer to finding worlds that can support life.
Newly Discovered Planets Likely Have Water On Their Surface
Finding exoplanets is not new. Earlier this month, for instance, scientists who were observing 1,600 stars using the W.M. Keck Observatory reported the discovery of 60 new planets, including one super-Earth, outside of the solar system.
The discovery of the seven new extraterrestrial worlds outside of the solar system, however, has caused much excitement to the scientific community NASA even called for a press conference.
The discovery is rare because the newly found planets are not just similar in size to Earth. Just like our home planet, the newly discovered planets are also temperate, which means they likely have water on their surface and may have potentials to support life.
The Goldilocks Zone
Another thing about some of the newly discovered exoplanets that is of particular interest to astronomers is where they orbit relative to their host, the dwarf star TRAPPIST-1.
Astronomers have long been interested in the so-called Goldilocks zone, the area around a star where the surface temperatures are neither too hot nor too cold to make possible for liquid water that can support life to exist. Three of the planets in the TRAPPIST-1 system are in this habitable zone. Researchers said that the star system now has the record for most rocky planets lying in the habitable zone.
Inviting Target For Finding Signs Of Alien Life
Researchers said that the potential habitability and location of the planets make TRAPPIST-1 an inviting target to search for extraterrestrial life. The newly found world could well be included in the lists of places where scientists look for signs of life. To date, scientists are already launching missions to find signs of life on planet Mars, Jupiter moon Europa, and Saturn moon Enceladus.
"This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life," said Thomas Zurbuchen, from NASA's Science Mission Directorate. "Answering the question 'are we alone' is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal."
Hunting For Signatures Of Life
To find possible signatures of life such as methane and oxygen in this star system, astronomers may take advantage of NASA's James Webb Space Telescope (JWST), which is set for launch late next year. The $8.8 billion telescope may shed more light on the atmospheres of the TRAPPIST-1 planets by the early 2020s.
Finding both methane and oxygen in the atmosphere could indicate the presence of life. The two gases destroy each other, explained Shawn Domagal-Goldman, from NASA's Goddard Space Flight Center.
"If they're both there together, you know someone is bringing the methane in an atmosphere rich in oxygen, so that's what you're looking for," Domagal-Goldman said. "The most likely explanation is, it's life that's bringing the methane and oxygen to the party."