Watch the moondust fly
Posted: Wednesday, September 06, 2006 7:56 PM by Alan Boyle
This weekend's crash of Europe's SMART-1 probe on the moon wasn't just a flash in the pan. The 4,475-mph (2-kilometer-per-second) smackdown raised enough of a puff of dust to be seen by the same camera that recorded the flash of impact - an infrared imager on the Canada-France-Hawaii Telescope on Mauna Kea in Hawaii. Researchers say it represents the first lunar crash and resulting dust cloud ever spotted from Earth.
CFHT |
An animated image from the
Canada France Hawaii Telescope
shows the flash of SMART-1's
impact, followed by a puff of dust
expanding from the impact site.
|
Lunar impacts have been observed from Earth before - ranging from the occasional meteoroid strike to the 1999 crash of NASA's Lunar Prospector probe. It's the cloud of debris that makes SMART-1's coup de grace special. Scientists weren't able to spot that signature from Lunar Prospector's crash, and the readings from SMART-1 could eventually shed new light on the composition of the lunar surface.
The dust cloud shows up amid faint "Earthshine" - the light reflected from our planet's sunlit disk back onto the dark areas on the moon's disk. The Hawaii observatory's series of photographs, taken every 15 seconds, indicates that the expanding cloud was visible for at least 75 seconds after the flash of impact.
In a statement, researchers at the Canada-France-Hawaii Telescope said the impact imagery "should allow observers to survey the area and look for the ejecta through imaging or spectroscopic observations."
"A careful analysis of the time evolution of the dust cloud, joined to the precise knowledge of the spacecraft dynamics at the time of the crash, should help to better understand the formation of ejecta following a lunar impact," the researchers said.
SMART-1 sent back plenty of its own imagery from its final days, including its view of a half-shadowed Earth and its last batch of lunar pictures. Check out the European Space Agency's Web site for more about the spacecraft's "swan song" - and check out our clickable tutorial on the ion propulsion technology that was successfully tested during Europe's first mission to the moon.
