Imagine walking on a planet that is full of diamond. Dubbed 55 Cancri e, an exoplanet twice the size of Earth, is composed of carbon mostly in the form of graphite and diamond. At least a third of the planet’s mass is likely diamond as a result of the temperatures and pressures in the planet’s interior. Further observations are necessary to confirm the nature of the planet. It orbits a Sun-like hot star called 55 Cancri A. Planets like this are vastly different from our Earth, which has relatively less carbon.
Astronomers discovered the planet in 2004 after looking at the spectrum of its parent star, 55 Cancri A, one of two stars in a binary system about 40 light-years from Earth in the constellation Cancer. There are at least four other planets in the same system, mostly discovered before 55 Cancri e. The team (led by the University of Texas at Austin’s Barbara McArthur) discovered subtle tugs on the parent star that could be explained by the presence of yet another planet. While the planet’s existence was challenged by a second research team in 2005, a separate team in 2006 confirmed it.
Astronomers initially thought 55 Cancri e (abbreviated 55 Cnc e) had an orbital period of 2.8 days, but measurements in 2011 showed that the planet is much closer to its parent star. Observations with Canada’s MOST (Microvariability & Oscillations of STars) space telescope demonstrated an orbital period of less than 18 hours. Researchers estimated the surface temperature of 55 Cancri e could be as high as 4,892 F (2,700 C).
Follow-up observations with the Spitzer Space Telescope in 2012 showed that 55 Cancri e is much weirder than anticipated. While original estimates said the planet was dense and rocky, Spitzer suggested the planet includes a healthy proportion of light elements and compounds (such as water). However, the planet’s high surface temperatures contribute to a “supercritical” fluid state, the researchers said, meaning that the gases are in a liquid-like state.
Credit : Space.com
Picture Credit : Google
