Starship Asterisk*

MargaritaMc wrote:When you made a guess you would ask 'Am I hot or cold?'.
So -

http://arstechnica.com/science/2011/08/ ... f-diamond/

am I hot or cold??

M

Beyond wrote:Margarita, ok... are you hot or cold

Beyond wrote:Hey Ann, is this close

Teardrop or whirlpool nebula

MargaritaMc wrote:

MargaritaMc wrote:When you made a guess you would ask 'Am I hot or cold?'.
So -

http://arstechnica.com/science/2011/08/ ... f-diamond/

am I hot or cold??

M

Is it still cold?

Yale researchers have discovered that a rocky super-Earth orbiting a nearby star is a diamond planet.

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” said Dr Nikku Madhusudhan, a Yale researcher in physics and astronomy and lead author of a paper to be published in the Astrophysical Journal Letters (arXiv.org version).

“The surface of this planet is likely covered in graphite and diamond rather than water and granite.”

The planet, called 55 Cancri e, has a radius twice Earth’s, and a mass eight times greater, making it a so-called super-Earth. It is one of five planets orbiting a sun-like star, 55 Cancri, that is located 40 light years from Earth yet visible to the naked 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.

55 Cancri e 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 the Yale team to infer its chemical composition using models of its interior and by computing all possible combinations of elements and compounds that would yield those specific characteristics.

Astronomers had previously reported that the host star has more carbon than oxygen, and the team confirmed that substantial amounts of carbon and silicon carbide, and a negligible amount of water ice, were available during the planet’s formation.

“Astronomers also thought 55 Cancri e contained a substantial amount of super-heated water, based on the assumption that its chemical makeup was similar to Earth’s,” Dr Madhusudhan said.

But 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. The study estimates that at least a third of the planet’s mass – the equivalent of about three Earth masses – could be diamond.

“By contrast, Earth’s interior is rich in oxygen, but extremely poor in carbon — less than a part in thousand by mass,” said co-author Dr Kanani Lee, geophysicist with Yale University.

“The identification of a carbon-rich super-Earth means that distant rocky planets can no longer be assumed to have chemical constituents, interiors, atmospheres, or biologies similar to those of Earth,” Dr Madhusudhan said.

The discovery also opens new avenues for the study of geochemistry and geophysical processes in Earth-sized alien planets. 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.

Moonlady wrote:Ok, we got a girl who is from a planet, then we got a diamond picture who could be from earth but also from other places in space,
I found 55 Cancri:

Yale researchers have discovered that a rocky super-Earth orbiting a nearby star is a diamond planet.

Ann wrote:

Click to view full size image

This is my puzzle. Two answers are equally possible!

Ann

WIKIPEDIA
Uranus is similar in composition to Neptune, and both are of different chemical composition than the larger gas giants Jupiter and Saturn. For this reason, astronomers sometimes place them in a separate category called "ice giants". Uranus's atmosphere, although similar to Jupiter's and Saturn's in its primary composition of hydrogen and helium, contains more "ices" such as water, ammonia, and methane, along with traces of hydrocarbons.[12] It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224 °C). It has a complex, layered cloud structure, with water thought to make up the lowest clouds, and methane thought to make up the uppermost layer of clouds.[12] In contrast, the interior of Uranus is mainly composed of ices and rock.[11]

Beyond wrote:Jools, jewels or joules. I pick jewels. I think you have solved Ann's fiendishly wicked puzzle, Margarita. Time to take the day off and recuperate

Ann wrote:Bystander, I wasn't even thinking of that planet, but... your answer is brilliant! Brilliant like a diamond, even!

Nature Physics 6, 40 - 43 (2010)
Published online: 8 November 2009 | doi:10.1038/nphys1438

Subject Categories: Condensed-matter physics | Materials physics

Melting temperature of diamond at ultrahigh pressure
J. H. Eggert1, D. G. Hicks1, P. M. Celliers1, D. K. Bradley1, R. S. McWilliams1,2, R. Jeanloz2, J. E. Miller3, T. R. Boehly3 & G. W. Collins1

Since Ross proposed that there might be ‘diamonds in the sky’ in 1981 (ref. 1), the idea of significant quantities of pure carbon existing in giant planets such as Uranus and Neptune has gained both experimental2 and theoretical3 support. It is now accepted that the high-pressure, high-temperature behaviour of carbon is essential to predicting the evolution and structure of such planets4. Still, one of the most defining of thermal properties for diamond, the melting temperature, has never been directly measured. This is perhaps understandable, given that diamond is thermodynamically unstable, converting to graphite before melting at ambient pressure, and tightly bonded, being the strongest bulk material known5, 6. Shock-compression experiments on diamond reported here reveal the melting temperature of carbon at pressures of 0.6–1.1 TPa (6–11 Mbar), and show that crystalline diamond can be stable deep inside giant planets such as Uranus and Neptune1, 2, 3, 4, 7. The data indicate that diamond melts to a denser, metallic fluid—with the melting curve showing a negative Clapeyron slope—between 0.60 and 1.05 TPa, in good agreement with predictions of first-principles calculations8. Temperature data at still higher pressures suggest diamond melts to a complex fluid state, which dissociates at shock pressures between 1.1 and 2.5 TPa (11–25 Mbar) as the temperatures increase above 50,000 K.

Lawrence Livermore National Laboratory, Livermore, California 94551, USA
University of California, Berkeley, California 94720, USA
University of Rochester, Rochester, New York 14623, USA