Earth
weighs 5973600000000000000000000kg, and a kilo of reasonable quality
diamonds currently fetches sums of $50 million and above. It orbits a
sun-like star 40 light years from Earth, so any mineral prospectors
would have quite a journey to stake their claim on its riches.
The
planet is twice as wide as Earth, and has a mass eight times greater.
It is thought to be covered in graphite – the material found in the
‘lead’ of pencils – and diamonds.
“This
is our first glimpse of a rocky world with a fundamentally different
chemistry from Earth,” said lead researcher Nikku Madhusudhan, a Yale
postdoctoral researcher in physics and astronomy.
“The surface of this planet is likely covered in graphite and diamond rather than water and granite.”
The
planet — called 55 Cancri e – is one of five planets orbiting a
Sun-like star, 55 Cancri, that is located 40 light-years from Earth yet
visible to the unclad eye in the constellation of Cancer.
The
planet orbits at hyper speed — its year lasts just 18 hours, in
contrast to Earth’s 365 days. It is also blazingly hot, with a
temperature of about 3,900 degrees Fahrenheit, researchers said, a far
cry from a habitable world. The planet was first observed transiting its
star last year, allowing astronomers to measure its radius for the
first time.
This
new information, combined with the most recent estimate of its mass,
allowed Madhusudhan and colleagues to infer its chemical composition
using models of its interior.
The scientists computed all possible combinations of elements and compounds that would yield those specific characteristics.
The
new research suggests the planet has no water at all, and appears to be
composed primarily of carbon (as graphite and diamond), iron, silicon
carbide, and, possibly, some silicates.
“By
contrast, Earth’s interior is rich in oxygen, but extremely poor in
carbon — less than a part in thousand by mass,” says co-author and Yale
geophysicist Kanani Lee.
“Stars
are simple — given a star’s mass and age, you know its basic structure
and history,” said David Spergel, professor of astronomy and chair of
astrophysical sciences at Princeton University, who is not a co-author
of the study. “Planets are much more complex. This ‘diamond-rich
super-Earth’ is likely just one example of the rich sets of discoveries
that await us as we begin to explore planets around nearby stars.”
In
2011, Madhusudhan led the first discovery of a carbon-rich atmosphere
in a distant gas giant planet, opening the possibility of long-theorized
carbon-rich rocky planets (or “diamond planets”).
The
new research represents the first time that astronomers have identified
a likely diamond planet around a Sun-like star and specified its
chemical make-up.
Source: Yahoo News
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