Energy News  
Reproducing GEMS In The Lab

The team said this is the first time a GEMS-like structure has been reproduced in the lab. Testing results show that the iron-oxide component undergoes a chemical reaction known as reduction, in which the iron gains electrons and releases its oxygen. Therefore the heated samples contained practically no iron in the silicate glass.
by Staff Writers
Les Ulis, France (SPX) Feb 14, 2006
French scientists said they have reproduced the structure of primitive interplanetary dust in the laboratory. Reporting in an upcoming issue of Astronomy & Astrophysics, the team said they have produced a compound called GEMS - for glass with embedded metal and sulfides - a major component of interplanetary dust.

Understanding the origins of the particles - samples of which recently were returned to Earth by NASA's Stardust spacecraft - is considered one of the major objectives of planetary science.

Team leader C. Davoisne and colleagues attempted to reproduce GEMS, which are only a few nanometers (billionths of a meter) in size and composed of a silicate glass that includes small, rounded grains of iron/nickel and metal sulfide. A small fraction of GEMS (less than 5 percent) floating in interplanetary space are thought to have formed before the solar system, and therefore are interstellar in origin. This mix of GEMS types has made it difficult, however, for scientists to sort out their origin and formation process.

Team members at two French laboratories - the Laboratoire de Structure et Propri�t�s de l'Etat Solide in Lille and the Institut d'Astrophysique Spatiale in Orsay - heated various amorphous samples of olivine - which is composed of manganese, iron oxide and silicon - under high vacuum and at temperatures ranging from 500 degrees to 750 degrees Celsius. After the heating, samples showed microstructures that closely resemble GEMS, with rounded iron nanograins embedded in a silicate glass.

The team said this is the first time a GEMS-like structure has been reproduced in the lab. Testing results show that the iron-oxide component undergoes a chemical reaction known as reduction, in which the iron gains electrons and releases its oxygen. Therefore the heated samples contained practically no iron in the silicate glass.

This is why dust observed around evolved stars and in comets is composed mainly of magnesium-rich silicates and apparently lacking in iron, the team said, because iron in metallic spherules becomes totally undetectable by the usual remote spectroscopic techniques. They added that the work could provide an important insight into the composition of interstellar grains as well.

The chemical process that produces GEMS could be quite common, both in the solar system and around other stars. The scientists said they are now awaiting the analysis of the grains collected by Stardust to find out whether some GEMS truly originated in the interstellar medium.

Community
Email This Article
Comment On This Article

Related Links
NASA Stardust
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Astronomers Find Planetary Disk With Opposing Rotations
Socorro, NM (SPX) Feb 13, 2006
Astronomers studying a disk of material circling a still-forming star in the Milky Way have discovered the inner part of the disk is rotating in the opposite direction of the outer part of the disk.







  • Garbage Truck Industry Ponders Move To LNG
  • Nuclear Fusion On A Tabletop
  • SCHOTT Solar Receiver To Power New Solar Thermal Power Plant
  • China Energy Quest Not A Threat

  • Outside View: The Future's Nuclear
  • Doubts Cast Over Viability Of US Nuclear Energy Plans
  • Russian deputies warn of radioactive contamination at nuclear plant
  • Germany Rethinks Phasing Out Nuclear Power

  • Yale To Study Atmospheric 'Tsunamis'4
  • What Is A Cloud
  • Getting To The TOPP Of Houston's Air Pollution
  • Scientists Seek Sprite Light Source

  • European Union Donates 38M Euros To Africa's Forests
  • Ecologists Mull Future Of Wetlands In Poor Countries
  • Satellites Show Amazon Parks And Indigenous Lands Stop Forest Clearing
  • Deforestation Threatens Brazil's Pantanal Wetland

  • New Research Network Aims to Protect Food Supply
  • Europe Downplays WTO Ruling Genetically Modified Crops
  • France To Adopt European Union Rules On Genetically Modified Grops
  • Outrage Over Indonesian Plans For Palm Oil Plantation In Rainforest

  • Volkswagen And Google Team Up To Explore Future Vehicle Nav Systems
  • NASA Technology Featured In New Anti-Icing Windshield Spray
  • Eclectic Koizumi Tries Electric Sedan
  • GM Hires Russian Nuclear Scientists To Develop New Auto Technology

  • New Technology Enhances Quality And Safety Of Military Aircraft
  • Around The World In 80 Hours
  • Lockheed Martin Highlights 5th Gen Fighters And Next Gen Airlift
  • Air Force Announces Quadrennial Defense Review And Budget Highlights

  • Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear
  • NASA plans to send new robot to Jupiter
  • Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission
  • Boeing Selects Leader for Nuclear Space Systems Program

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement