Welcome to the third entry in my series on exoplanets based on NASA's Exoplanet Travel Bureau site. The site itself provides the gorgeous vintage travel posters and guided tours, but I wanted to do a deeper dive into these exoplanets.
55 Cancri e is officially named Janssen, which was voted on by the International Astronomical Union's (IAU) NameExoWorlds program, which was launched in 2014. It was discovered in 2004 by a team of astronomers using the radial velocity method, which involves measuring the wobbling motion of the host star caused by the gravitational pull of the orbiting planet. 55 Cancri e orbits the star 55 Cancri, also known as Copernicus. 55 Cancri is a binary star system consisting of a G-type main-sequence star (55 Cancri A) and a smaller, dimmer star (55 Cancri B). The planet orbits 55 Cancri A very closely, completing one orbit in just 18 hours. Its proximity to the star places it in the "ultra-short-period" category of exoplanets.
55 Cancri e is an exoplanet that has gained significant attention due to its unique characteristics and its potential as a super-Earth, with a mass approximately eight times that of Earth and roughly twice the diameter, making it one of the largest known exoplanets. It has a high density that suggests it's likely composed of heavy elements such as rock and metal. Due to its close proximity to its host star, 55 Cancri e experiences extreme temperatures. It's one of the hottest exoplanets known, with surface temperatures that can reach up to 2,400 degrees Celsius (4,352 degrees Fahrenheit). It's so hot that it's likely to have a surface of molten lava or even a rocky core surrounded by a thick atmosphere of vaporized rock.
The presence and composition of an atmosphere on 55 Cancri e are still being studied. Given its high temperatures and proximity to its host star, any atmosphere it might have could be volatile and constantly changing. Because of its extreme surface conditions, 55 Cancri e is not considered a habitable planet; it lacks the conditions necessary for life as we know it.
55 Cancri e is of particular interest to astronomers and planetary scientists because of its unusual characteristics. It provides valuable insights into the diversity of exoplanets and the wide range of conditions that can exist in other planetary systems. Research on this exoplanet continues to deepen our understanding of the formation and evolution of different types of planets beyond our solar system.