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3 planets discovered in nearby solar system vastly different from our own

Image: NASA’s Goddard Space Flight Center/Scott Wiessinger
Image: NASA’s Goddard Space Flight Center/Scott Wiessinger

Three newly discovered planets just 73 light-years from our own are helping scientists learn more about the diverse solar systems that populate our galaxy, according to a new study in the journal Nature Astronomy.

Key takeaway: The 3 worlds all reside in the TOI-270 star system, a solar system that is very different from our own.

  • Two of the planets — TOI 270c and TOI 270d — are about half the size of Neptune, and the other is slightly larger than Earth.
  • The “sub-Neptunes” represent a type of planet that doesn’t exist in our solar system.

The big picture: Scientists hope to study solar systems wildly different from our own in order to gain a better understanding of just how unique our solar system is in the grand scheme of things.

Details: The three newfound planets — found by NASA’s Transiting Exoplanet Survey Satellite (TESS) — orbit a star that is much smaller and dimmer than our Sun.

  • TOI 270b orbits the star every 3.4 Earth days and is just slightly larger than Earth, but it’s extremely hot at 490°F (254°C) on average.
  • TOI 270c is slightly farther from its star, with an almost 6-day orbit, and it is likely covered by a dense atmosphere.
  • The sub-Neptune that’s farthest from its star — TOI 270d — may have an upper atmosphere conducive to some forms of life, but below its clouds, the surface is probably uninhabitable, scientists say.

Go deeper: An orrery of TESS' planets