Three new planets, which orbit a star situated 73 light-years away from the Earth, have been discovered using NASA’s newest planet-hunting satellite. Of the three new exoplanets, one is rocky and slightly larger than Earth, while the two others are gaseous and roughly twice the size of our planet. The new star system, called TESS Object of Interest, or TOI-270, is exactly what the Transiting Exoplanet Survey Satellite, or TESS, was designed to find, said researchers from the University of California, Riverside in the US.
  1. Not only is the smaller planet in the habitable zone — the range of distances from a star that is warm enough to allow liquid-water oceans on a planet — but the TOI-270 star is nearby, making it brighter for viewing.
  2. There are no planets about half the size of Neptune in our solar system, though these are common around other stars.
  3. TOI-270 will soon allow us to study this “missing link” between rocky Earth-like planets and gas-dominant mini-Neptunes because here all of these types formed in the same system.
  4. Follow-up observations on the system have been planned for 2021 when the James Webb Space Telescope launches. It will be able to measure the composition of the TOI-270 planets’ atmospheres for oxygen, hydrogen, and carbon monoxide.
  5. These kinds of observations can help determine whether a planet has ever had a liquid water ocean and whether any of the planets have conditions suitable for life as we know it.
  6. While TOI-270 is far enough away that no one living will likely ever travel there, at 73 light-years away it is still considered close, researchers said.
  7. The diameter of our galaxy is 100,000 light-years, and our galaxy is just one of the millions of galaxies. So, 73 light-years means it’s one of our neighbouring stars.