Diamond crushed to Saturn’s extremes

Jul 20, 2014

By James Morgan


Diamond, nature’s hardest material, has been crushed to record extremes of pressure using the “world’s biggest laser”, US scientists report.

The carbon crystal was condensed to the core pressure of Saturn – 14 times that at the centre of the Earth.

The big squeeze was performed inside the US National Ignition Facility, which recently featured in Star Trek.

It gives clues to the conditions deep inside giant, carbon-rich planets, says a study in Nature journal.

“We don’t know what lies within the core of Jupiter or Saturn but now for the first time we now have the ability to study how matter exists under these extreme conditions of pressure and temperature,” said lead author Dr Ray Smith, of Lawrence Livermore National Laboratory, California.

“Our experiments provide a method for recreating conditions within the cores of giant gas planets – both within our solar system and beyond.

“It has been proposed, for example, that Neptune has a diamond in its core, due to decomposition of methane which gets compacted under extreme pressure.

“The Kepler space mission has found Neptune-sized planets to be very common in our galaxy.”

The planets and stars we see in the night sky were formed by powerful gravitational forces that crushed their constituent atoms tightly together.

The extreme pressures in their cores are expected to cause dramatic changes to the properties of matter.

How, on Earth, we can replicate these alien environments is a terrific challenge for scientists.

The US National Ignition Facility (NIF) was built to study inertial confinement nuclear fusion, and features 192 lasers which are used to bombard materials with energy.

Its target chamber famously doubled as the Starship Enterprise’s “warp core” in the movie Star Trek: Into Darkness.

US researchers used NIF to compress carbon via a technique known as “dynamic ramped compression”.

They focused 176 laser beams onto a millimetre-scale target diamond, held at the centre of a 10m aluminium sphere.

“The challenge in our experiments was keeping temperatures low enough to be relevant to gas giant planets like Jupiter,” Dr Smith told BBC News.

“We accomplished this by carefully tuning the rate at which the laser intensity changes with time. The problem is similar to moving a plough slowly enough that sand is being pushed forward without building up in height.”

The combined energy of the lasers (0.76 megaJoules, or MJ) created pressure waves in the diamond, compressing it to five terapascals (50 million atmospheres) – similar to the pressure at the centre of Saturn.

5 comments on “Diamond crushed to Saturn’s extremes

  • There are whole new fields of chemistry and physics, once we move away from the familiar Normal-Temperatures-and Pressures of sea-level Earth.

    Whole new worlds of science in planetary cores, giant planets, Black-Holes, Neutron stars etc.

    Report abuse

  • There is a side of this story that is missing from the account. The tool used, NIF, has been a massive failure for what it is funded for which is a research tool for maintenance of the massive U.S. thermonuclear weapon stockpile. It failed to meet it’s ignition goal yet it is still being funded as a nuclear weapon research tool. It’s always been pitched to the public as a viable path to fusion power production to gain their support. It is not.

    Beam Us Up

    National Ignition Facility Fails

    Report abuse

  • This is a fascinating subject that I was looking forward to learning about. Unfortunately Mr. Morgan has merely posted a series of single sentence “factoids” that are often unrelated to each other and never fleshed out. It’s like reading items in a celebrity bio: “I love bacon!” “I have a moped.” “Puppies are so cute.” “My parents encouraged me.” Individually these one-liners are useless and, when taken as a whole, are lazy and amateurish. This reads like a mediocre eighth-grade general science class report. Speaking of eighth-grade writing, you may want to encourage your “writers” to include a grammar check along with their spell check before they publish their “articles”.

    Report abuse

  • @OP link – “There are two standard models,” Dr Smith told BBC News.
    . . . .

    “The core accretion model suggests Jupiter was initially formed as a 10-Earth-mass body which had sufficient gravitational pull to trap and accumulate the large, thick hydrogen atmosphere we observe today.
    . . . . .
    “Another model, the giant instability model, proposes these giant gas planets were formed due to density instabilities which give rise to gravitational fluctuations and eventual clumping together of hydrogen gas – i.e. they formed without the need for a core.”

    These models have considerable implications for the distribution of planets throughout galaxies.

    If both models are planet forming, planets will be wide-spread, but rocky ones may be absent in low metallicity – solar systems of the giant instability model.

    If a core of heavy elements is required for planet formation, there may be no planets in low metallicity star clusters, if the giant instability model is invalid.

    Report abuse

Leave a Reply

View our comment policy.