103 meteoroid impacts on Moon in 2.5 years

William Atkins
Wednesday, 21 May 2008 22:18

Science - Space

A list of all 103 impacts is found at NASA Marshall Space Flight Center’s website “Lunar Impacts.”

Plus, a picture showing all 103 impact locations is found within the previously mentioned article “100 Explosions on the Moon.”

In the beginning of their search the MEO astronometers used one 10-inch telescope. However, now, the astronomers use three telescopes to view lunar impacts: two of them at the Marshall Space Flight Center (14-inch [36-centimeter] and 20-inch [51-centimeter]) and one at a newly established site in Georgia (14-inch).

Although the astronomers have seen quite a few impacts on the Moon, Cooke says that future astronauts will be safe on the Moon. He states, "The odds of a direct hit are negligible. If, however, we start building big lunar outposts with lots of surface area, we'll have to carefully consider these statistics and bear in mind the odds of a structure getting hit."

Cooke is more concerned with secondary impacts; that is, debris (ejecta) sent flying in all directions after the primary hit from the meteoroid occurs on the Moon’s surface.

NASA states, “A single meteoroid produces a spray consisting of thousands of ‘secondary’ particles all traveling at bullet-like velocities. This could be a problem because, while the odds of a direct hit are low, the odds of a secondary hit may be significantly greater.

Cooke warns, "Secondary particles smaller than a millimeter could pierce a spacesuit.”

To simulate the spray of particles from a meteoroid impact, the MEO astronomers are shooting (at speeds up to 16,000 miles per hour [7 kilometers per second]) artificial meteoroids (0.25-inch Pyrex glass beads) at “simulated lunar soil” (manufactured here on Earth) to measure the physical characteristics of the spray, especially how far it travels.

The simulation is being performed at the Ames Vertical Gun Range (AVGR) at NASA’s Ames Research Center (Mountain View, California, U.S.A.).