Planet 55 Cancri e is a super-Earth located in the 55 Cancri system that orbits its Sun-like star at a very close distance. It has a diameter of 16,116 km, larger than Earth’s (12,742 km), and an extremely high temperature (2400 degrees Celsius) due to its narrow orbit. Near the Earth’s core, the temperature is about 5700 degrees Celsius. On the Earth’s surface, the average temperature is about 16 degrees. At the same time, the melting point of iron is approximately 1.538 degrees Celsius. The planet’s composition is still unknown, but it is believed to be made of carbon-rich material. The planet has a high carbon-to-oxygen ratio, with about one-third of its mass being carbon, and may contain diamonds due to the high temperatures and pressures inside.
Credit: Foto: ESA/Hubble, M. Kornmesser
This temperature is sufficient to vaporize diamonds on the planet, and this vaporized material can condense to form diamond rain. This diamond rain can then be recycled back to the planet’s surface, creating an endless cycle. Conditions on the planet are so extreme that some scientists speculate that a layer of liquid diamond may be on the planet’s surface.
In 2011, scientists calculated the density of 55 Cancri e, which showed that it contains more carbon than oxygen and may also contain volatiles such as carbon dioxide instead of water or hydrogen. Although 55 Cancri e was thought initially to be a diamond planet, it is more like a “diamond in the rough” as further observations are needed to determine its composition.
How does the composition of Planet 55 Cancri e make it a diamond planet?
The planet 55 Cancri e orbits a star in the constellation Cancer. Previously, it was believed this was the first planet consisting mainly of diamonds. The planet has a mass similar to Earth, but its surface is composed of graphite rather than water and granite. In addition, the planet’s iron abundance is too high to contain carbon-rich material. Despite this evidence, the composition of Planet 55 Cancri e still makes it a diamond planet due to its high temperature and pressure.
The planet is about 40 light-years from Earth and orbits its host star, 55 Cancri A. The planet’s host star is a yellow dwarf slightly brighter than the Sun.