William Atkins
Thursday, 29 January 2009 20:32
Science -
Space
Page 3 of 4
Wieczorek and Le Feuvre analyzed the characteristics of the Moon, specifically, its size and velocity before and after this hypothetical impact, with probably an asteroid or a comet.
This analysis was based on data collected over the years by spacecraft imaging the craters on the Moon’s surface. They made special note on the location and age of the craters.
Wieczorek states,
"Just based on the physics, it's very, very, very probable that at least one and perhaps more of these impacts did this to the moon. The second question, and this is the harder part, is finding if there's any evidence of this or not." [Scientific American: “
Flip-Flop: Did the Moon Do a Turnabout?”]
Thus, the scientists contend that the craters should be denser on its western hemisphere, which is the leading hemisphere in the current orbit of the Moon.
In the Scientific American article, Wieczorek, a planetary geophysicist, compares this to
“… driving a car in a storm—more rain hits the front windshield than the rear.”
The Scientific American article continues,
“The analysis revealed that whereas the younger impact basins follow this pattern, the older ones tend to be found on the trailing side of the moon, indicating that the moon has swiveled 180 degrees about its axis since those ancient craters formed. According to their calculations, in fact, the arrangement of older impact basins near the now-trailing eastern hemisphere has less than a 0.3 percent probability of happening by chance.”
The two scientists are now confident that current and future lunar orbiters will provide additional information to substantiate their claims.
Are they correct in their conclusion, or is there another explanation? Please read page four.
