The discovery of exoplanets is very developed in comparison to some years ago. Each day new planets are discovered orbiting stars very far away from ours’, and which aren’t very similar to the planets that orbit the Sun. Even so, in 2011, a team of scientists discovered a planet formed mainly by carbon, orbiting a star at 40 light years from the Earth. It can be said that it is a planet of diamonds.
Facts about 55 Cancri e
This planet is known as a super-earth. It is a rocky planet that orbits around a star from the Cancer constellation, similar to the Sun, at 40 light years from the Earth. 55 Cancri e is twice the size of the Earth, but however it has a mass 8 times bigger than the one of our planet.
55 Cancri e is so close to its star, that it orbits around it every 18 terrestrial hours. This planet always shows to its star the same face. This phenomenon also happens in the case of the Moon: there is a face that is never visible from the Earth, the named hidden face of the moon.
The diamond planet
The carbon, essential element for the organic matter to appear, is one of the most valuable components appreciated by the humanity, as the diamonds or the petroleum, formed from this material. Despite this importance, the carbon is a very rare material: it only represents the 0,1% of our planet.
Whereas, at 55 Cancri e, the carbon can be as common as the soil. The elevated temperatures of 55 Cancri e, of about 2150Cº, are caused by the quick rotation of the planet and its proximity to its star. Thanks to these big temperatures and to the pressions the planet is subdued to, it provoques the carbon to convert, massively, into diamonds.
The planet 55 Cancri e could have a graphite crust of some hundreds of kilometres of thickness. According to Nikku Madhusudhan, postdoctoral astrophysicist and investigator from the Yale university, under it there is an enormous diamond cape. It is though that the diamonds represent approximately a third part of the thickness of the planet.
This discovery changed the way in which we understand the planetary chemistry, as our solar system is formed out of a lot of oxygen and silicates, while this stellar system is mainly formed out of carbon. What the scientists think is that the formation of these planets would be different to the Earth’s, as they hypothesise that they could be formed from a nebula that would contain carbon in much bigger quantities than oxygen.