(Sen) - A rocky planet studded with possible diamonds may forever change the way that astronomers view the composition of rocky worlds.
A group of Yale University researchers reported that 55 Cancri e – a planet double Earth's size and eight times its mass in the constellation Cancer – has a surface that is probably blanketed in graphite and diamond.
The star that 55 Cancri e orbits around is so bright and so close, at 40 light years away from Earth, that it is visible with the naked eye from Earth. There are five known planets in its solar system.
A star map showing where 55 Cancri e's star is in the constellation Cancer. The star is visible with the naked eye, but easier to spot with binoculars. Credit: Nikku Madhusudhan, using Sky Map Online
Although 55 Cancri e is a rocky planet, it's tucked in very close to the sun. It whips around its orbit just once every 18 days. There's also little chance that life could exist on this planet, as its temperature is estimated to be at 3,900 degrees Fahrenheit.
“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” stated lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher who focuses on physics and astronomy.
There are two main ways of measuring a planet: calculating its radius by watching it transit a star, or measuring its mass by watching a star "wobble" as the planet goes by. In the case of Cancri 55 e, researchers measured its radius last year. This new research combines estimates of its mass with calculations of what its composition could be.
This diamond world research shows that astronomers should be careful about exoplanet assumptions, according to Madhusudhan. While it's common for astronomers to make hypotheses on other planets based on what we know about Earth and our Solar System, this vastly different composition implies that may not always be the best way to understand other solar systems.
"The discovery also opens new avenues for the study of geochemistry and geophysical processes in Earth-sized alien planets," Yale stated in a press release.
"A carbon-rich composition could influence the planet’s thermal evolution and plate tectonics, for example, with implications for volcanism, seismic activity, and mountain formation."
Results will be published in the journal Astrophysical Journal Letters.