Mohith AgadiScientists have discovered a new planet not too far from our solar system which might have the most habitable condition next to Earth. The planet revolves around a cool star and it is 1.4 times larger than earth and has 6.6 times Earth’s mass. The planet named LHS 1140b is 39 light years away and it revolves around the dwarf star called LHS 1140. The planet completes one revolution in 24 days.
According to a study published in the scientific journal Nature, the position of the planet in relation to its sun is just right; it is neither too hot nor too cold so presence of liquid water on its surface is a distinct possibility. A very exciting fact about this planet is that because it lies only 39 light years away from Earth, it is possible to analyze and learn more about its atmosphere with the telescope that Earth already has. It is possible that Giant Magellan Telescope and Hubble Space Telescope can even spot oxygen in the atmosphere of LHS 1140b.
There is however a problem; M-dwarfs or red dwarfs are dwarf stars that burn brightly and throw out big flares, so planets in its immediate vicinity can be stripped off their atmosphere within a timeframe of 3 billion years. But evidence has been found that some planets around red dwarfs can hold onto their atmosphere. For example, GJ 1132b, a planet that orbits a red dwarf and has temperatures like Venus, still has its atmosphere.
“There has been lots of debate about whether these planets can maintain a magnetic field (and if that’s important for habitability) and if M-dwarf planets lose their atmospheres in their host star’s active youth,” said Jason Dittman of the Harvard-Smithsonian Center for Astrophysics who is also the lead author of the study. “This debate definitely isn’t settled, and there are compelling reasons why these planets might lose their atmospheres and there are also ways that you can imagine it can hold onto its atmosphere.”
Till date, over 3500 planets outside of our solar system have been discovered, and the number is growing at a steady pace as the powerful telescopes in Earth look further and further. But they have never discovered a habitable M-dwarf planet with its atmosphere intact. LHS 1140b is the first of its kind in this regard. LHS 1140, the red dwarf is a older star its days of furious flares left behind. So, if there is indeed an atmosphere around LHS 1140b then it is highly likely that the planetary atmosphere still exists.
Ananya Dutta
