Interstellar Dust in the Wind
April 24, 2000
-- Like an excited kid hoping to snag a fly ball at a professional
baseball game, NASA's Stardust spacecraft has extended its high-tech
"catcher's mitt" to collect a valuable space souvenir
-- a batch of interstellar dust particles.
The dust is contained in a stream of particles that flows through our solar system, and scientists are anxious to study it so they can learn more about the formation of Earth, other planets and life.
Right now, Stardust is oriented so that the interstellar dust particles are hitting the backside of the collector. This collection began on February 22, when the spacecraft's sample return capsule opened and the aerogel collector was moved out of the capsule. It will remain in this configuration until May 1, when the collector will return to its stowed position for safe storage until mid-2002, when another period of interstellar dust collection is scheduled.
Right: Nobody really knows what a typical interstellar dust grain looks like. By studying how dust absorbs, emits, and reflects light, astronomers do know that interstellar dust is much different than the cell and lint based dust found around a typical house. Recent work indicates that most dust grains are not spherical. The above picture shows the result of a fractal adhesion model for dust grains involving random conglomerates of spherical compounds of different properties, here artificially highlighted by different colors. [more information]
"The project's name, 'Stardust,' reflects the importance of this event," said Stardust Project Manager Dr. Kenneth Atkins of NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. "It's the first time anyone has attempted to catch anything like this and bring it home. After all the design, building, testing, and now the flying of this spacecraft over the past four years, the moment of truth for the collector is here. These tiny particles zip by at 20 to 25 kilometers per second (about 45,000 to 56,000 miles per hour) relative to the spacecraft. The aerogel must slow them to a stop in fractions of an inch."
Left: Dust particles shot into a sample of
aerogel during ground tests created these microscopic tracks
in the translucent, ultra-lightweight material.
In late December 2003, the collector will be deployed again in preparation for the gathering of comet dust samples when Stardust flies by Comet Wild-2 on January 2, 2004. Once the samples of both interstellar dust and comet dust are tucked safely inside the aerogel collector, it will be retracted into the sample return capsule. Stardust will begin the return trip to Earth and make a soft landing at the U.S. Air Force's Utah Test and Training Range in 2006. The sample canister will be taken to the planetary material curatorial facility at NASA's Johnson Space Center, Houston, Texas. The samples will be carefully extracted and then examined by scientists.
"I'm thrilled at the thought of being able to look at and study these particles firsthand," Brownlee said.
More information on the Stardust mission is available at http://stardust.jpl.nasa.gov/ .
Stardust was launched on February 7, 1999. The mission is managed by JPL for NASA's Office of Space Science, Washington, D.C. Lockheed Martin Astronautics, Denver, Co, built and operates the spacecraft. Science instruments were provided by JPL, the University of Chicago and the Max Planck Institute, Garching, Germany. JPL is a division of the California Institute of Technology, Pasadena.
The Science of STARDUST -- from JPL
STARDUST Education web page -- from JPL
Why comet Wild-2? -- from the JPL STARDUST team
Where is comet Wild-2 right now? -- from the JPL STARDUST team, updated every 5 minutes
Orbital elements of comet Wild-2 -- from the JPL STARDUST team
More about aerogel -- from JPL