Post by Chicago Astronomer - Astro Joe on Feb 16, 2006 14:12:07 GMT -6
"Backward" Running planets
Wed, 15 Feb 2006 - NASA astronomers have discovered an unusual solar system about 500 light-years away where the inner planets are going one direction, and the outer planets are going in the opposite direction. This newly forming system is quite different from our own Solar System, where the planets and the Sun all turn in the same direction. It's possible that the system formed from two different clouds of material, which were rotating in opposite directions.
Our solar system is a one-way boulevard. All the planets - from Mercury out to Pluto and even the newly discovered objects beyond - revolve around the Sun in the same direction. This is because the Sun and planets formed from the same massive, rotating cloud of dust and gas. The motion of that cloud set the motion of the planets.
The fact that a solar system can have planets running in opposite directions is a shocker.
"This is the first time anyone has seen anything like this, and it means that the process of forming planets from such disks is more complex than we previously expected," said Anthony Remijan of the National Radio Astronomy Observatory.
"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 budding solar system 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.
The VLA observations of the "beltway" solar system revealed the motion of silicon monoxide (SiO) molecules. These emit radio waves at about 43 GigaHertz (GHz). When Remijan and Hollis compared 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.
This is the first time such a phenomenon has been seen in a disk around a young star. Yet who's to say the arrangement is uncommon? As astronomers find more and more extra-solar planets (over a hundred so far and counting), they are realizing that solar systems come in many shapes and sizes.
The VLA comprises 27 radio antennas spread out across 36 kilometers in a Y formation outside of Socorro, N.M. This is the site featured in the movie Contact. The National Radio Astronomy Observatory operates the facility.
Full story on Universe Today: www.universetoday.com/am/publish/backwards_planets.html?1522006
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Who's to say that we won't find planets orbiting All Over the Place...in orbits 90 degrees from the "normal" orbit plane we are used to.