Nasa's planet hunting mission finds three new 'worlds'

Transiting Exoplanet Survey Satellite (TESS), Nasa’s new planet hunter discovered three new exoplanets. These are outside the solar system.

They orbit a star called TOI 270, only 73 light-years away. The TOI system includes a small, rocky super-Earth and two sub-Neptunes, which may be a missing link in planetary formation, say astronomers.

Unlike our solar system, where each planet is different in terms of size, the size of exoplanets is very similar. 

TOI-270 is an M-dwarf, a type of star that is normally extremely active, with frequent flares and solar storms. But, in this system it appears to be an older M-dwarf that has since quieted down, giving off a steady brightness.

These unique characters help scientists measure properties of orbiting planets like mass and atmospheric composition. The MIT-developed satellite analyses sky patches for 27 days at a time, monitoring thousands of stars for possible movement.

Any peculiar dip in brightness could be planet temporarily blocking the star’s light. The team isolated several such signals from a nearby star and confirmed that the signals were the result of three orbiting exoplanets.

One planet initially showed a habitable zone that could support water, but TESS scientists later confirmed the planet’s atmosphere is thick and will generate greenhouse gases that will increase temperatures, making it uninhabitable.

The team hopes research will reveal more planets, one of which may have the ability to form water and be habitable. The researchers plan to focus on other instruments, including the upcoming James Webb Space Telescope, on TOI-270, to understand various properties of the three planets.

Science & Technology India