Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists get first close look at stardust

28.02.2003


For the first time, scientists have identified and analyzed single grains of silicate stardust in the laboratory. This breakthrough, to be reported in the Feb. 27 issue of Science Express, provides a new way to study the history of the universe.


"Astronomers have been studying stardust through telescopes for decades," said first author Scott Messenger, Ph.D., senior research scientist in the Laboratory for Space Sciences at Washington University in St. Louis. "And they have derived models of what it must be like, based on wiggles in their spectral recordings. But they never dreamed it would be possible to look this closely at a grain of stardust that has been floating around in the galaxy."

Most stardust is made of tiny silicate grains, much like dust from rocks on earth. Away from city lights, you can see the dust as a dark band across the Milky Way. This dust comes from dying and exploded stars. Scientists think stars form when these dust clouds collapse and that some of this dust became trapped inside asteroids and comets when our own sun formed.

The researchers found the stardust in tiny fragments of asteroids and comets--interplanetary dust particles (IDPs) --collected 20 km above the earth by NASA planes. A typical IDP is a mishmash of more than 100,000 grains gleaned from different parts of space. Until recently, ion probes had to analyze dozens of grains at one time and so were able to deduce only the average properties of a sample.



In 2001, with help from NASA and the National Science Foundation, Washington University bought a newly available and much more sensitive ion probe. Made by Cameca in Paris, the NanoSIMS probe can resolve particles as small as 100 nanometers in diameter. A million such particles side by side would make a centimeter. The grains in IDPs range from 100 to 500 nanometers. "So like the Hubble telescope, the NanoSIMS allows us to see things on a much finer scale than ever before," Messenger said.

Lindsay P. Keller, Ph.D., at NASA’s Johnson Space Center in Houston, first examined thin slices of IDPs under the transmission electron microscope. He identified the chemical elements in single grains and determined whether the grains were crystals or coated with organic material.

Using the NanoSIMS probe, the Washington University investigators then measured the relative amounts of two isotopes of oxygen in more than a thousand grains from nine IDPs. The data told them which grains had come from stars. The researchers discovered the first grain of stardust in the first half hour of their first NanoSIMS session. "Finding something that people have been seeking for such a long time was incredibly exciting," Messenger said.

Stardust was surprisingly common in the IDPs. "We found that 1 percent of the mass of these interplanetary dust particles was stardust," Messenger explained. "So stardust is about 50 times as abundant in these particles as in meteorites, which suggests that it comes from far more primitive bodies."

The isotopic measurements identified six stardust grains from outside our solar system. Three appeared to have come from red giants or asymptotic giant branch stars, two late stages in stellar evolution. A fourth was from a star containing little metal. The fifth and sixth possibly came from a metal-rich star or a supernova.

Although this work is just beginning, some novel findings have emerged. For example, one of the grains was crystalline, which contradicts the idea that silicate stardust grains are always amorphous. "A single grain of stardust can bring down a long-established theory," Messenger said.

The researchers will probe the history of stardust with further studies of IDP chemistry and microstructure. "The interstellar medium plays an incredibly important role in star formation, but you can learn only so much by using a telescope," Messenger said. "You can find out so much more by studying actual samples."



A grant from NASA funded this research.
Images of IDPs are available.

Tony Fitzpatrick | EurekAlert!
Further information:
http://www.wustl.edu/
http://stardust.wustl.edu
http://www.sciencemag.org/feature/express/expresstwise.shl

More articles from Physics and Astronomy:

nachricht New quantum phenomena in graphene superlattices
19.09.2017 | Graphene Flagship

nachricht Solar wind impacts on giant 'space hurricanes' may affect satellite safety
19.09.2017 | Embry-Riddle Aeronautical University

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: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

New quantum phenomena in graphene superlattices

19.09.2017 | Physics and Astronomy

A simple additive to improve film quality

19.09.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>