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10 April 2014 11:44 am ,
Vol. 344 ,
Tight budgets are forcing NASA to consider turning off one or more planetary science projects that have completed their...
Ebola is not a stranger to West Africa—an outbreak in the 1990s killed chimpanzees and sickened one researcher. But the...
In an as-yet-unpublished report, an international panel of geoscientists has concluded that a pair of deadly...
Tropical disease experts tried and failed before to eradicate yaws, a rare disfiguring disease of poor countries. Now,...
Since 2002, researchers have reported that agricultural communities in the hot and humid Pacific Coast of Central...
Balkan endemic kidney disease surfaced in the 1950s and for decades defied attempts to finger the cause. It occurred...
The Pyrenean ibex, an impressive mountain goat that lived in the central Pyrenees in Spain, went extinct in 2000. But a...
- 10 April 2014 11:44 am , Vol. 344 , #6180
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ScienceShot: Solar System's Origins Not So Special
23 February 2012 3:01 pm
When it comes to the size of its protoplanetary disk, our solar system is just an average Joe. That’s what researchers will report in an upcoming issue of The Astronomical Journal about the extent of dust and gas from which our planetary system first formed. Using observational data and computer models that rewound the solar system back to the time of Jupiter's formation some 4.56 billion years ago, the team argues that our protoplantary disk stretched no farther than 80 astronomical units, roughly double the distance of Pluto's orbit. If the disk had been any bigger, gravitational forces within it would have pushed some icy bodies smaller than Pluto outward into steeply tilted orbits—a situation astronomers have not observed in our solar system. While disks around other young stars can run the gamut from tens to thousands of astronomical units, the average is roughly 60 AU. So even though we might think we’re special, the galaxy would tend to disagree.
See more ScienceShots.