New model explains formation of the Earth's Moon
Posted: Sat, Oct 20, 2012, 8:47 AM ET (1247 GMT)
Scientists this week reported that they have developed new models of the formation of the Earth's Moon that reconciles one of the leading explanations with the compositions of the two worlds. The model, published in the latest issue of the journal Science, is based on the giant impact explanation for the creation of the Moon, where a Mars-sized protoplanet struck the early Earth, throwing off debris that formed the Moon. While that model had become widely accepted, it could not explain why the two worlds had similar ratios of oxygen isotopes. The new model uses much larger impactors, up to five times the mass of Mars. This creates oxygen radios similar for both world, although they produce an Earth rotating up to 2.5 times as fast as expected from the existing angular momentum of the Earth-Moon system. However, a companion paper explains how that angular momentum could have been reduced soon after the Moon's formation through a resonant interaction between the Moon and Sun.
Scientists this week reported that they have developed new models of the formation of the Earth's Moon that reconciles one of the leading explanations with the compositions of the two worlds. The model, published in the latest issue of the journal Science, is based on the giant impact explanation for the creation of the Moon, where a Mars-sized protoplanet struck the early Earth, throwing off debris that formed the Moon. While that model had become widely accepted, it could not explain why the two worlds had similar ratios of oxygen isotopes. The new model uses much larger impactors, up to five times the mass of Mars. This creates oxygen radios similar for both world, although they produce an Earth rotating up to 2.5 times as fast as expected from the existing angular momentum of the Earth-Moon system. However, a companion paper explains how that angular momentum could have been reduced soon after the Moon's formation through a resonant interaction between the Moon and Sun.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
|
|
news links
|
|
Monday, May 20
Those magnificent spooks and their spying machine: The spies help rescue Skylab
The Space Review — 4:06 pm ET (2006 GMT) Kepler’s uncertain future
The Space Review — 4:05 pm ET (2005 GMT) Futures imperfect
The Space Review — 4:04 pm ET (2004 GMT) Review: Mission to Mars
The Space Review — 4:02 pm ET (2002 GMT) British astronaut Tim Peake set for launch
Financial Times — 7:58 am ET (1158 GMT) |
