Scientists have discovered a new planetary system made up of two distant worlds that could be home to alien life.
The two planets are in orbit around a tiny, cold star designated LP 890-9. After the equally interesting TRAPPIST-1, it is the second-coolest star to contain planets.
One of the planets in the system is known as LP 890-9b, and it is just 30% the size of Earth. A year takes only 2.7 days because it is so close to that cold star.
In addition, the system has another, previously unknown planet known as LP 890-9c. The planet is comparable in size to the first, being 40% larger than Earth, but has a longer year, taking 8.5 days to orbit the star.
The new study was conducted with the use of ground-based telescopes known as Speculoos - Search for livable Planets EClipsing ULtra-cOOl Stars. Because very cold stars, such as LP 890-9b, are difficult to detect with space telescopes, this type of follow-up study is required.
Scientists started the fresh observations in the hopes of verifying the existence of the first planet, which was discovered as a candidate world by Nasa's Transiting Exoplanet Survey Satellite, which searches for planets outside our solar system. But the observations also found that second planet.
That latter planet is in the star's "habitable zone," which means it is neither too hot nor too cold for extraterrestrial life to exist.
"The habitable zone is a concept in which a planet with similar geological and atmospheric conditions as Earth would have a surface temperature that allows water to remain liquid for billions of years," explained Amaury Triaud, a professor of Exoplanetology at University Birmingham and the leader of the Speculoos working group that scheduled the observations that led to the discovery of the second planet.
“This gives us a license to observe more and find out whether the planet has an atmosphere, and if so, to study its content and assess its habitability.”
Reference(s): Independent