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 Discovery of an Extragalactic Hot Molecular Core
29.09.2016 | National Astronomical Observatory of Japan

nachricht Swiss space research reaches for the sky
29.09.2016 | Schweizerischer Nationalfonds SNF

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: New welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HLF: From an experiment to an establishment

29.09.2016 | Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

 
Latest News

New Multiferroic Materials from Building Blocks

29.09.2016 | Materials Sciences

Silicon Fluorescent Material Developed Enabling Observations under a Bright “Biological Optical Window”

29.09.2016 | Materials Sciences

X-shape Bio-inspired Structures

29.09.2016 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>