Astronomers have recently discovered a rocky exoplanet with an atmosphere, a characteristic deemed crucial for the potential to support life.

Significant Findings:

  • Mass and Size: The Planet 55 Cancri e, also known as Janssen, is about 8.8 times more massive than Earth with a diameter roughly twice as large.
  • Location: The planet is located 41 light-years away from Earth in the constellation Cancer, within the Milky Way galaxy.
  • Type: It is classified as a “super-Earth,”. It orbits very close to its host star with an orbital period of 18 hours.
  • Atmosphere: Infrared observations from the James Webb Space Telescope suggest the presence of a substantial atmosphere, possibly replenished by gases from a vast magma ocean. The atmosphere likely contains carbon dioxide or carbon monoxide, and possibly water vapour and sulfur dioxide.
  • Its atmosphere could be as thick as Earth’s or even thicker than that of Venus, whose toxic atmosphere is the densest in our solar system
  • Surface Temperature: Surface temperatures reach around 3,140 degrees Fahrenheit (1,725 degrees Celsius) Due to its proximity to its star, making it one of the hottest rocky exoplanets discovered.
  • Tidal Locking: The planet is likely tidally locked; meaning it’s one side permanently facing its star, similar to Earth’s moon.
  • Host Star System: Its host star is part of a binary system, gravitationally bound to a red dwarf star at a significant distance.
  • Habitability: Despite having an atmosphere, the extreme temperatures make liquid water impossible, rendering the planet uninhabitable.


  • A “super-Earth” is a type of exoplanet with a mass larger than Earth’s but significantly less than that of the ice giants Uranus and Neptune. 
  • Super-Earths can have a wide range of compositions, which might include gas, rock, or a combination of both.


  • Unlike previous exoplanet discoveries which primarily involved gas giants, this finding advances the understanding of rocky exoplanets with atmospheres.
  • 55 Cancri e is one of the first discovered super-Earths orbiting a Sun-like star.
  • It helps us understand the diversity of planetary systems in the universe.
  • The discovery raises hopes for similar investigations on cooler planets that could potentially support liquid water, although further exploration is needed.

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