NASA recently announced its discovery of seven earth-like exoplanets orbiting around a single star around 40 light years away. Three of these exoplanets are said to be firmly located in the habitable zone. The discovery has set a record for the highest number of habitable-zone planets around a single star outside of our solar system. Researchers state the possibility of liquid water in all these seven planets more so in the ones in the habitable zone.
NASA observed this star called Trappist -1 in the Aquarius constellation and two of the seven planets continuously for 20 days with the help of Spitzer Space Telescope. The data collated revealed that what scientists thought to be a single planet were in reality four of them that orbited their star approximately every 4, 6, 9 and 12 days. These joined the two already discovered planets that revolved around the star every 1.5 days and 2.4 days. The seventh one is more distant.
As per lead author Michael Gillon, the six inner planets formed farther from their star and eventually migrated inward. They are now so close to one another that the gravitational fields of these interact. The mass of these planets ranges from around 0.4 to 1.4 times the mass of Earth.
The newly found system is quite close to earth and it is thus easy to gather details about it. The other habitable zone planets detected until now are mostly hundreds of light years away.
NASA has reportedly developed a telescope that can be used to understand the atmospheres of these exoplanets. It is set to be launched in 2018. This solar system is said to be very different from ours. Trappist-1 is a tiny dwarf star. It is about a tenth of the mass of the sun and is around one-thousandth time as bright. The low mass of this star allows its planets to revolve around very close to it and remain in the habitable zone.
The distance at which these Earth-like planets orbit around their star is almost the same as that of Jupiter to its moons. These are said to be so close to each other that if a person was standing on one then he could see the geological features of the other. Studies also indicate that the same side of the planet always faces the star and thus each of the side is either perpetual day or night. This means that they may have weather pattern completely different from that of Earth.
“With this discovery we’ve made a giant, accelerated leap forward in our search for habitable worlds and life on other worlds potentially”, said Sara Seager, a leading exoplanet expert at MIT.