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6 March 2014 1:04 pm ,
Vol. 343 ,
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
- 6 March 2014 1:04 pm , Vol. 343 , #6175
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ScienceShot: Moon Formed From Head-On Collision
3 August 2012 10:43 am
Some 4.53 billion years ago, a Mars-sized impactor slammed into Earth, forming a young, molten moon. But was it a head-on collision or a glancing blow? New computer simulations argue for the former, indicating that the impactor scored a direct hit, crashing into Earth at a steeper angle and with a higher velocity than previously thought. The resulting smashup would have ejected far more Earth debris into space than other models have indicated, with much hotter temperatures. And that would mean the moon formed from more Earthlike material than previously thought. The origin of the impactor itself remains an open question. The slow impact velocity of previous models requires it to have originated from an orbit very near Earth, while the new model allows for an origin from more far-flung parts of the solar system, researchers report in an upcoming issue of Icarus.
See more ScienceShots.