What is Gliese 12b?

About Gliese 12b:

• It is a newly discovered temperate, Earth-sized exoplanet orbiting a cool red dwarf called Gliese 12, located in the constellation Pisces.
  • Red dwarfs have lower luminosity, which means their habitable zones are much closer to the star.
  • Gliese 12 is about 27% the size of our sun and 60% of its temperature.
• Gliese 12 b is located 40 light-years away, which is relatively close in astronomical terms. 
• Since its star is so much smaller than the sun, Gliese 12b still falls within the habitable zone—the ideal distance away from a star where liquid water can exist—even though it completes its orbit every 12.8 days.
• Gliese 12 b is roughly the size of Earth or slightly smaller, making it comparable to Venus.
  • This similarity in size makes Gliese 12 b an excellent subject for studying rocky planets.
• Its mass is approximately 3.87 times that of Earth.
• It receives 1.6 times more energy from its star than Earth does from the Sun, and about 85% of what Venus experiences.
• The estimated surface temperature of Gliese 12 b is 107°F (42°C), assuming it has no atmosphere.

About Transiting Exoplanet Survey Satellite (TESS):

• It is a NASA mission to discover exoplanets around nearby bright stars.
• Launch: It was launched on April 18, 2018, aboard a SpaceX Falcon 9 rocket out of Cape Canaveral.
• Orbit: TESS circles Earth in a unique high Earth orbitof 12 to 15 days, which is inclined in a way that the telescope’s sky view is largely free from obstructions by our bright planet and the Moon.
• The prime mission ended on July 4, 2020, and TESS is now on an extended mission.
• TESS is finding planets ranging from small, rocky worlds to giant planets, showcasing the diversity of planets in the galaxy.
• How does TESS find exoplanets?
  • It uses the transit method to detect planets.
  • It looks for periodic dips in stars' brightness as planets cross in front of them along our sightline.
  • The larger the planet, the further the drop in brightness during the transit. 
  • How long it takes a planet to pass in front of the star and come back tells us the shape of its orbit.
  • This method reveals the diameter of the planet and the size of its orbit. 
  • Orbits within a certain range lie in the “habitable zone”, where liquid water can exist on the surface of an Earth-like world.