The Planet Uranus - Articles - Zimbio

A Gem of a Story

Sun, 11 Jun 2007 20:19:00 GMT

posted by DoctorWill

In 1981, Marvin Ross, a scientist from the Lawrence Livermore National Laboratory, published a paper in the journal Nature suggesting the center of Uranus and Neptune might turn out to be a girl’s best friend. To understand why, we first need to look at the make-up of these planets. Uranus and Neptune are comprised of three layers, namely, a rocky center, a liquid layer (water, methane, and ammonia), and a low-calorie outer layer consisting of hydrogen and helium. Ross suggested that the high pressure and temperature of the second layer would cause the pyrolysis of methane (a very cool word for burnt-to-a-crisp). Under these conditions, methane would break down and release free carbon molecules (Question: what does carbon under pressure form?). In order to prove this, Ross designed an experimental system that allowed him to analyze the behaviour of methane when exposed to conditions believed to exist on these planets. Methane is a compound consisting of one molecule of carbon with four molecules of hydrogen (i.e. a hydrocarbon). When methane was exposed to Neptune-like conditions, the bonds between carbon and hydrogen broke apart. This left a mixture of elemental carbon and molecular hydrogen with the potential to form, you guessed it, diamonds. These results have been further confirmed using high energy laser pulses that converted methane into diamond dust at temperatures and pressures comparable to those believed to exist within Neptune and Uranus. Combine these observations with the fact that carbon makes up nearly 17% of Neptune and Uranus’ planetary mass and you start to imagine a diamond with ginormous proportions.

Which leads me to my next post, what could we do with all that diamond anyway? I know, build an elevator!

mybiblio

Marvin Ross. (1981). The ice layer in Neptune and Uranus – diamonds in the sky? Nature. 292: 435-436.

Laura Robin Benedetti, Jeffrey H. Nguyen, Wendell A. Caldwell, Hongjian Liu, Michael Kruger, and Raymond Jeanloz (1999) Dissociation of CH₄ at High Pressures and Temperatures: Diamond Formation in Giant Planet Interiors? Science. 286: 100-102

Raining Diamonds in Uranus and Neptune

Tue, 7 Nov 2007 14:31:00 GMT

posted by cooluks
Uranus seen through the space shuttle voyager 2

The said planets contain a high amounts of methane, which the UC Berkeley researchers now shown can turn into diamond at very high temperatures and pressures found inside these planets.

Experiments done at the University of California, Berkeley, are the indication of future explorers of our solar system that they may find diamonds falling down through the atmospheres of Neptune and Uranus. Berkeley - October 1, 1999

"Once the diamonds form, they will fall like raindrops or hailstones toward the center of the planet," explained by Laura Robin Benedetti, graduate student in physics at UC Berkeley.

The team, led by Benedetti and Raymond Jeanloz, professor of geology and geophysics, produced these conditions inside a diamond anvil cell, squeezing liquid methane to several hundred thousand times atmospheric pressure. When focused a laser beam on the pressurized liquid, heating it to some 5,000 degrees Fahrenheit, diamond dust appeared.

They report their experimental findings in a paper in the Oct. 1 issue of Science. The demonstration that methane can convert to diamond as well as other complex hydrocarbons in the interiors of giant planets like Neptune hint at a complex chemistry inside gaseous planets and even brown dwarf stars. Brown dwarfs are small, dim stars barely larger than the largest gas giant planets.

"This is opening the door to study of the interesting types of chemical reactions taking place inside planets and brown dwarfs," Jeanloz said. "Now that technology is able to reproduce the high pressures and temperatures found there, we are getting much better quality information on the chemical reactions taking place under these conditions."

"It is not amazing that chemistry like this happens inside planets, it's just that most people haven't dealt with the chemical reactions that can occur," Benedetti said. "The interior of these planets may be much more complicated that our current picture."

A simple calculation, for example, shows that the energy released by diamonds settling to the planet's core could account for the excess heat radiated by Neptune, that is, the heat given off by Neptune in excess of what it receives from the sun.

"What's exciting to us is the application of this high-pressure chemistry to understanding the outer planets," Jeanloz said.

"As more planets are found in unexpected orbits around other stars, the effects of internal chemical processes will need to be further clarified in order to obtain a general understanding of planet formation and evolution," the authors concluded in the Science paper.

Possible structure of Neptune

Our solar system's other gas giant planets, Jupiter and Saturn may also contain diamonds produced under such conditions, though they contain proportionately less methane than Neptune and Uranus. Based on theoretical calculations, Neptune and Uranus are estimated to contain about 10 to 15 percent methane under an outer atmosphere of hydrogen and helium. (See the above image for presumed internal structure of Neptune)

Several groups of researchers have suggested that the methane in these planets could conceivably turn into diamond at fairly shallow depths, about one tenth of the way to the center. Nearly two decades ago, a group at Lawrence Livermore National laboratory shocked some methane and reported the formation of diamond before the stuff evaporated. That group was led by retired scientist Marvin Ross and researchers William Nellis and Francis Ree.

The Major Moons of Uranus

Mon, 28 Oct 2008 18:46:06 GMT

posted by dc64
Mighty blue Uranus dares to be different, for unlike his planetary siblings, he has chosen his companions from the literary works of William Shakespears and Alexander Pope. Here we will seek out the wonders of the five largest moons of Uranus.

Welcome to our blog about The Planet Uranus

Thu, 30 Jun 2006 01:03:16 GMT

posted by Tony
This is our group blog, which is unique because any Zimbio member can post an entry to it. Some members blog about recent news and trends related to the portal topic, others recount relevant personal stories. You can also comment on and rate existing blog entries, to voice your opinion and to help the community identify which members and entries on the portal are must-reads. Got an interesting idea or story to share with other members of this portal? Well, then put on your journalist's cap and add your own blog entry!