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 LP 890-9, a small, cool star. After the equally intriguing TRAPPIST-1, it is the second-coolest star to host planets.
One of the planets in the system is known as LP 890-9b, and it is only 30% the size of Earth. A year takes only 2.7 days because it is so close to that cool star.
In addition, the system contains another, previously unknown planet known as LP 890-9c. The planet is similar 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 help of ground-based telescopes known as Speculoos – Search for habitable 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 observation is required.
Scientists started the new observations in the hopes of confirming the existence of the first planet, which was discovered as a potential world by Nasa’s Transiting Exoplanet Survey Satellite, which searches for
planets outside our solar system. However, the observations also discovered a second planet.
“Habitable zone”
That latter planet is in the star’s “habitable zone,” which means it is neither too hot nor too cold for alien life to exist.
“The habitable zone is a concept under which a planet with similar geological and atmospheric conditions as Earth, would have a surface temperature allowing water to remain liquid for billions of years” said Amaury Triaud, a professor of Exoplanetology at University Birmingham and the leader of the Speculoos working group that scheduled the observations leading 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.”
