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Pile of rubble a record of solar system's history UNIVERSITY OF MICHIGAN NEWS RELEASE Posted: June 3, 2006 A small, near-Earth asteroid named Itokawa is just a pile of floating rubble, probably created from the breakup of an ancient planet, according to a University of Michigan researcher who was part of the Japanese space mission Hayabusa. The finding suggests that asteroids created from rubble would be pristine records of early planet formation. A global view of the Asteroid Itokawa, with white box showing region where the Hayabusa spacecraft landed to collect samples. Daniel Scheeres, U-M associate professor of aerospace engineering, was part of the team that determined the asteroid's mass, surface environment, and gravitational pull and helped interpret the images that were taken of the asteroid from the spacecraft. Some of the findings will be discussed in a special issue of the journal Science on June 2. The mission is led by the Japan Aerospace Exploration Agency. The Hayabusa space probe arrived at asteroid Itokawa last fall and orbited for three months. During that time it descended twice to the surface of the asteroid, which is named for the father of Japanese rocketry, to collect samples. In 2010 the probe will return to Earth and eject a sample canister that will reenter the atmosphere and land in central Australia. Researchers hope this will be the first asteroid sample brought back to Earth. Scheeres said that the confirmation of Itokawa's makeup as rubble rather than a single rock has large implications for theories of how asteroids evolved, and will lead to a better understanding of the early solar system. Asteroids are thought to be the remnants of material that formed the inner planets, which include Earth, and could bear the record of events in the early stages of planet formation. It is a significant finding that Itokawa is a pile of rocks ranging in size from tiny sand grains all the way up to boulders 50 meters wide, because it verifies a number of theories about the makeup and history of asteroids. The existence of very large boulders and pillars suggests that an earlier "parent" asteroid was shattered by a collision and then re-formed into a rubble pile, the researchers conclude in the paper. It's likely that most asteroids have a similar past, Scheeres said. "Analysis of the asteroid samples will give us a snapshot of the early solar system, and provide valuable clues on how the planets were formed." Also, knowing if an asteroid is a single, big rock or a pile of rubble will have a major influence on how to nudge it off course, Scheeres said, should its orbit be aimed at Earth. An asteroid collision with Earth, while unlikely, could have disastrous consequences. It's widely thought that an asteroid collision caused the mass extinction of dinosaurs 65 million years ago, so some have discussed ways to demolish or steer an approaching asteroid, should we see one coming. Another striking finding, Scheeres said, is that regions of Itokawa's surface are smooth, "almost like a sea of desert sand" and others are very rugged. This indicates that the surfaces of asteroids are, in some sense, active, with material being moved from one region to another. Gravity holds the mass of rubble together. "These are the first such detailed observations of an asteroid from this close," Scheeres said. The University of Michigan College of Engineering is ranked among the top engineering schools in the country. Michigan Engineering boasts one of the largest engineering research budgets of any public university, at more than $130 million. Michigan Engineering has 11 departments and two NSF Engineering Research Centers. Within those departments and centers, there is a special emphasis on research in three emerging areas: nanotechnology and integrated microsystems; cellular and molecular biotechnology; and information technology. Michigan Engineering is seeking to raise $110 million for capital building projects and program support in these areas to further research discovery. Michigan Engineering's goal is to advance academic scholarship and market cutting-edge research to improve public health and well-being. |
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Space shuttle Columbia began mission STS-61C with a beautiful sunrise launch in January 1986 after several delays. Led by commander Hoot Gibson, the astronauts deployed a commercial communications satellite and tended to numerous experiments with the Materials Science Laboratory, Hitchhiker platform and Getaway Special Canisters in the payload bay. The crew included Congressman Bill Nelson of Florida, the first U.S. Representative to fly in space. Watch this post-flight film narrated by the astronauts.
The Boeing Delta 4 rocket launches from pad 37B at Cape Canaveral Air Force Station with the GOES-N spacecraft, beginning a new era in weather observing for the Americas.
As night fell over Kennedy Space Center on May 19, space shuttle Discovery reached launch pad 39B to complete the slow journey from the Vehicle Assembly Building. Discovery will be traveling much faster in a few weeks when it blasts off to the International Space Station.
The November 1985 flight of space shuttle Atlantis began with a rare nighttime blastoff. The seven-member crew, including a Mexican payload specialist, spent a week in orbit deploying three communications satellites for Australia, Mexico and the U.S. And a pair of high-visibility spacewalks were performed to demonstrate techniques for building large structures in space. The crew narrates the highlights of STS-61B in this post-flight crew film presentation.
Eight astronauts, the largest crew in history, spent a week in space during the fall of 1985 aboard shuttle Challenger for mission STS-61A, the first flight dedicated to the German Spacelab. The crew worked in the Spacelab D-1 laboratory conducting a range of experiments, including a quick-moving sled that traveled along tracks in the module. A small satellite was ejected from a canister in the payload bay as well. The astronauts narrate the highlights of the mission in this post-flight film.