New evidence of a distant planet with diamond continents and seas of molten graphite will prove rich fodder for sci-fi fans.
But the diamond â€œsuper-Earthâ€ â€” known as 55 Cancri e and twice the diameter of our planet â€” holds even more exciting possibilities for astrophysical science, says lead researcher Nikku Madhusudhan, a postdoctoral fellow at Yale Universityâ€™s Center for Astronomy and Astrophysics.
Until now, far-off rocky planets were assumed to be oxygen-rich and carbon-poor, just like Earth. But the new research suggests 55 Cancri e is the reverse.
â€œItâ€™s a much bigger event than just finding a planet,â€ says Madhusudhan. â€œWe are, for the first time, trying to explore the chemistry of planets outside the solar system. We are making the first marks.â€
Astronomers first spotted the planet transiting its host sun late last year. (That sun is 40 light years from Earth, yet visible to the naked eye in the constellation of Cancer.) By observing the planetâ€™s movements with a powerful telescope, they determined its radius and mass.
Assuming a carbon-poor composition similar to Earthâ€™s, astronomers could only make sense of the planetâ€™s dimensions by hypothesizing that it sat inside a pocket of â€œsupercriticalâ€ water.
Madhusudhan and his co-authors â€” Kanani Lee, a geophysicist at Yale, and Olivier Mousis, a planetary scientist at the Institut de Recherche en Astrophysique et PlanÃ©tologie in Toulouse, France â€” flipped that assumption on its head.
â€œWe come in, we ask the question: well, what if the planet is not Earth-like?â€source : http://www.thestar.com/news/world/2012/10/11/huge_diamond_planet_found_twice_the_size_of_earth.html