Astronomers have long been searching for rocky planets outside of our solar system that have an atmosphere, as this is considered essential for the potential of harboring life. Recently, researchers have located a rocky planet beyond our solar system that seems to have an atmosphere. However, this planet is not habitable, as it has a surface of molten rock, making it a hellish environment. This planet, known as 55 Cancri e or Janssen, is a super-Earth that is significantly larger than our planet but smaller than Neptune. It orbits a star that is dimmer and slightly less massive than our sun, completing an orbit every 18 hours.
Observations using the James Webb Space Telescope indicated the presence of a substantial atmosphere on 55 Cancri e, though it is likely rich in carbon dioxide or carbon monoxide. The thickness of the atmosphere remains unclear, but it is speculated to be as thick as Earth’s or even thicker than that of Venus. This planet is one of the hottest-known rocky exoplanets, with a surface temperature of 3,140 degrees Fahrenheit. It is likely tidally locked, meaning that one side perpetually faces its star, much like the moon does towards Earth. Despite being located 41 light-years from Earth in the constellation Cancer, 55 Cancri e is not a hospitable place and not suitable for life.
Surprisingly, the fact that 55 Cancri e even has an atmosphere is unexpected, considering its proximity to its star. Being so close to the star should strip away the atmosphere due to stellar irradiation and winds. However, gases dissolved in the vast lava ocean on the planet may continuously replenish the atmosphere. While this discovery represents a significant advancement in exoplanet exploration, 55 Cancri e is too hot to have liquid water, which is considered a prerequisite for life. Previous exoplanets found to have atmospheres were gaseous planets, not rocky ones, making this finding unique.
The star that 55 Cancri e orbits is part of a binary system, gravitationally bound to another star that is a red dwarf. The distance between these companions is vast, and it takes light six days to travel from one star to the other. Despite the inhospitable nature of 55 Cancri e, the discovery of a rocky exoplanet with an atmosphere signifies a step forward in the exploration of exoplanets. The atmosphere plays a crucial role on Earth, warming the planet, containing oxygen for breathing, protecting against solar radiation, and creating the necessary pressure for liquid water to remain on the surface. While 55 Cancri e is not habitable, there is hope that with further exploration, similar investigations could be conducted on cooler planets that could potentially support liquid water and, thus, life.
