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System found where planets may orbit backward NATIONAL RADIO ASTRONOMY OBSERVATORY NEWS RELEASE Posted: February 14, 2006 Astronomers studying a disk of material circling a still-forming star inside our Galaxy have found a tantalizing result -- the inner part of the disk is orbiting the protostar in the opposite direction from the outer part of the disk.
"The solar system that likely will be formed around this star will include planets orbiting in different directions, unlike our own solar system in which all the planets orbit the Sun in the same direction," Hollis explained. Stars and planets, scientists believe, are formed when giant clouds of gas and dust collapse. As the cloud collapses, a flattened, rotating disk of material develops around the young star. This disk provides the material from which planets form. The disk and the resulting planets rotate in the same direction as the original cloud, with the rotation speed increasing closer to the center, much as a spinning figure skater spins faster when they draw their arms inward. If all the material in the star and disk come from the same prestellar cloud, they all will rotate in the same direction. That is the case with our own solar system, in which the planets all orbit the Sun in the same direction as the Sun itself rotates on its axis. In the case of a young star some 500 light-years from Earth in the direction of the constellation Ophiuchus, Remijan and Hollis found the inner and outer parts of the disk rotating in opposite directions. "We think this system may have gotten material from two clouds instead of one, and the two were rotating in opposite directions," Remijan said. There is sufficient material to form planets from both parts of the disk, he added. The object is in a large, star-forming region where chaotic motions and eddies in the gas and dust result in smaller cloudlets that can rotate in different directions. In the solar system that probably will form around this young star, the innermost planets will orbit in one direction and the outer planets will orbit in the opposite direction. The scientists studied the star-forming clouds by analyzing radio waves emitted at specific, known frequencies by molecules within the clouds. Because the molecules emit radio waves at specific frequencies, shifts in those frequencies caused by motions (called Doppler Shift) can be measured, revealing the direction in which the gas is moving relative to Earth. The newest VLA observations of the region showed the motion of silicon monoxide (SiO) molecules, which emit radio waves at about 43 GigaHertz (GHz). When the astronomers compared their new VLA measurements of the motion of SiO molecules close to the young star with earlier measurements of other molecules farther away from the protostar, they realized the two were orbiting the star in opposite directions. Though this is the first time such a phenomenon has been seen in a disk around a young star, "Similar structures and dynamics commonly occur on small and large scales throughout the Universe. Thus, it is not surprising to find counter-rotation in a protostellar disk since the phenomenon has been previously reported in the disks of galaxies," Hollis said. The astronomers' report on their results will appear in the April 1 edition of the Astrophysical Journal. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. |
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Columbia's STS-3 mission is best remembered in the history books for its conclusion -- the first and so far only landing at the picturesque Northrup Strip at White Sands, New Mexico. In this post-flight presentation film, the crew describes the highlights of the March 1982 mission and shows some of the fun they had in orbit. The commander also tells how he accidentally "popped a wheelie" before bringing the nose gear down to the runway surface.
Seven months after the successful maiden voyage of space shuttle Columbia, astronauts Joe Engle and Richard Truly took the orbiter back into space on mission STS-2. The November 12, 1981 launch demonstrated that the space shuttle was the world's first reusable manned spacecraft. Although their mission would be cut short, Engle and Truly performed the first tests of the shuttle's Canadian-made robotic arm. The crew tells the story of the mission in this post-flight presentation.
The space shuttle era was born on April 12, 1981 when astronauts John Young and Bob Crippen rode Columbia into Earth orbit from Kennedy Space Center's launch pad 39A. The two-day flight proved the shuttle could get into space as a rocket and return safely with a runway landing. Following the voyage of STS-1, the two astronauts narrated this film of the mission highlights and told some of their personal thoughts on the flight.
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The flight of shuttle Discovery in October 1998 captured the public's attention with the triumphant return to space by John Glenn. The legendary astronaut became the first American to orbit the Earth some 36 years earlier. His 9-day shuttle mission focused on science experiments about aging. This post-flight presentation of highlights from the STS-95 mission is narrated by the astronauts.
Space shuttle Atlantis and a multinational crew flew to the Russian space station Mir in June 1995 for the first in a series of joint docking missions, launching a new era of cooperation in space between the United States and Russia that would pave the way for the International Space Station. This post-flight presentation of highlights from the historic STS-71 mission is narrated by the astronauts.
On the 20th anniversary of the space shuttle Challenger tragedy, a memorial service was held at the Kennedy Space Center's Space Mirror. Speakers at the tribute to honor the lost Challenger, Columbia and Apollo 1 astronauts included the widow and son of Challenger commander Francis "Dick" Scobee, officials with the Astronauts Memorial Foundation, two local U.S. Representatives, commander of the first shuttle flight after Challenger and the Kennedy Space Center director.
The New Horizons spacecraft begins a voyage across the solar system to explore Pluto and beyond with its successful launch January 19 aboard a Lockheed Martin Atlas 5 rocket from Cape Canaveral, Florida.