Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Comet Particles Provide Glimpse of Solar System’s Birth

18.11.2008
Scientists are tracking the violent convulsions in the giant cloud of gas and dust that gave birth to the solar system 4.5 billion years ago via a few tiny particles from comet Wild 2.

These convulsions flung primordial material billions of miles from the hot, inner regions of the gas cloud that later collapsed to form the sun, out into the cold, nether regions of the solar system, where they became incorporated into an icy comet.

“If you take a gas of solar composition and let it cool down, the very first minerals to solidify are calcium and aluminum-rich,” said Steven Simon, Senior Research Associate in Geophysical Sciences at the University of Chicago. And comet Wild 2 does contain these and other minerals formed at high temperatures. “That’s an indication of transport from the inner solar system to the outer solar system, where comets are thought to have formed,” he said.

Simon presents his data in the November 2008 issue (expected to be published early next year) of Meteoritics and Planetary Science. His 11 co-authors include Lawrence Grossman, Professor in Geophysical Sciences at the University of Chicago.

Either turbulence within the nebula, or a phenomenon called bipolar outflow from the early sun could account for the long-distance transport of cometary material, according to Simon and his Meteoritics co-authors.

Bipolar outflow results when the rotating disks that surround developing new stars jet gas from their polar regions, which astronomers have observed telescopically. “That’s part of the so-called X-wind model, which is somewhat controversial,” Simon said.

The controversial aspect of the X-wind model is the claim that the process would produce the kind of granules that Simon and his colleagues have now identified in comet Wild 2. Another less likely possibility: The cometary material in question may have formed around another star of composition similar to the sun, then drifted into the outer reaches of the solar system. There it became incorporated into comet Wild 2.

The extraterrestrial dust particles that Simon and his colleagues examined were among thousands that NASA’s Stardust spacecraft collected from comet Wild 2 in January 2004. Two years later, Stardust became the first mission to return samples of a comet to Earth.

Simon, Grossman and collaborators identified all three particles described in the Meteoritics study as pieces of a shattered refractory inclusion, one of the most unusual and informative materials discovered in early analyses of the Wild 2 samples. Such inclusions, found in some meteorites, formed by condensation from the gas in the solar nebula at temperatures of more than 2,500 degrees Fahrenheit early in the history of the solar system.

The three particles were named Inti, Inti-B and Inti-C, after the Incan sun god. The original, unbroken particle would have measured no more than 30 microns across, much narrower than a human hair.

As Simon, Grossman and a team of colleagues reported in 2006, Inti contains a suite of minerals that likely were forged in fiery conditions found deep inside the cloud of gas and dust that formed the sun, Earth and the planets. And yet comets probably formed in the outer reaches of the solar system, far beyond Neptune.

Contributing to an array of scientific analyses in the Meteoritics article were co-authors David Joswiak, Donald Brownlee and Graciela Matrajt of the University of Washington; Hope Ishii, John Bradley, Miaofang Chi, Jerome Aléon, Stewart Fallon and Ian Hutcheon of Lawrence Livermore National Laboratory in California; and Kevin McKeegan of the University of California, Los Angeles.

Most of this team, including Simon and Grossman, were among the 75 co-authors who published the first analysis of the comet Wild 2 particles in the Dec. 15, 2006, issue of the journal Science. A striking aspect of the Science and Meteoritics studies is the similarity in chemical composition between the Wild 2 samples and particles from carbonaceous chondrite meteorites. These meteorites contain material that has been unaltered since the birth of the solar system 4.5 billion years ago.

Equally striking is the complete lack of any water-bearing minerals in the cometary grains. Carbonaceous chondrites are rich in hydrated silicates, clay-like minerals that emit water when heated, “but there’s no hydrated silicate in the comet sample,” Grossman said.

Scientists organized the Stardust mission with the expectation that Wild 2’s samples would reveal a bonanza of exotic minerals, including debris from stars that had met their demise long before the birth of the sun. They may need to

rethink how comets formed, according to Grossman.

“Because they’re loaded with ices we’ve always thought that these are outer solar system objects,” he said. “But maybe cometary ices formed much closer in, after the inner part of the solar nebula cooled off, and incorporated the high-temperature stuff that formed earlier.”

The Stardust mission was scientifically important because comets are usually out of reach, Grossman said. And yet aside from the sun, they may be the most abundant material in the solar system. “There may be more stuff in the comets than in all the planets put together,” he said.

Steve Koppes | Newswise Science News
Further information:
http://www.uchicago.edu

Further reports about: COMET Earth GLIMPSE Geophysical Inti Meteoritics SOLAR Stardust X-wind birth particles solar system

More articles from Physics and Astronomy:

nachricht Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics

nachricht What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>