UK scientists sift superfine Stardust

A UK consortium of researchers from the University of Leicester, Natural History Museum, Kent University, Glasgow University and Open University have been studying the cometary samples which were delivered a few weeks after the samples were returned to Earth. The interstellar dust particles are about ten nanometres across (one hundred thousandth of a millimetre) and they are even smaller than many of the particles that Stardust collected when it flew through the coma of Comet Wild 2.

In a presentation at the Royal Astronomical Society's National Astronomy Meeting in Preston on 18th April, Dr John Bridges from the University of Leicester will describe how techniques developed to analyse material from the comet's tail will be used to study the interstellar particles. A focussed beam of electrically charged particles will be used to extract the residue of the dust from the craters. Once the material is no longer shielded by the crater walls, it can be examined using a transmission electron microscope.

“The interstellar dust particles collected by Stardust are so tiny that they pose huge analytical challenges,” said Dr Bridges. “Having spent the time perfecting our techniques and analysing Comet Wild 2, we are very excited by the prospect of these samples. Our analysis of samples from the comet's tail revealed that its composition was more complex than we'd thought and indicated an unexpected mixing of refractory and volatile material in the early Solar System. The interstellar particles will take us one step farther back and allow us to look at the composition of the dust cloud from which the Solar System formed.”

The Stardust mission spent 4 months collecting interstellar dust during its 2.88 million mile journey to Comet Wild-2 and back to Earth. The return capsule, containing the dust and samples from the comet's tail, landed in the desert in Utah in January 2006. Since then, samples have been distributed to selected researchers around the world.

FURTHER INFORMATION

The Stardust Mission

Stardust, a project under NASA's Discovery Program of low-cost, highly focused science missions, was built by Lockheed Martin Space Systems, Denver, Colorado, and is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. The mission's Principal Investigator is Dr. Donald Brownlee of the University of Washington in Seattle, WA. UK involvement is funded by the Science and Technology Facilities Council.

More information on the Stardust mission is available at http://stardust.jpl.nasa.gov/home/index.html.