Astronomy Picture of the Day
    


The Missing Craters of Asteroid Itokawa
<< Yesterday 21.11.2005 Tomorrow >>
The Missing Craters of Asteroid Itokawa
Credit & Copyright: ISAS, JAXA
Explanation: Where are the craters on asteroid Itokawa? No one knows. The Japanese robot probe Hayabusa recently approached the Earth-crossing asteroid and is returning pictures showing a surface unlike any other Solar System body yet photographed -- a surface possibly devoid of craters. One possibility for the lack of common circular indentations is that asteroid Itokawa is a rubble pile -- a bunch of rocks and ice chunks only loosely held together by a small amount of gravity. If so, craters might be filled in whenever the asteroid gets jiggled by a passing planet -- Earth in this case. Alternatively, surface particles may become electrically charged by the Sun, levitate in the microgravity field, and move to fill in craters. Over the weekend, Hayabusa lowered itself to the surface of the strange asteroid in an effort to study the unusual body and collect surface samples that could be returned to Earth in 2007.

January
February
March
April
May
June
July
August
September
October
November
December
 < November 2005  >
Mo Tu We Th Fr Sa Su

123456
78910111213
14151617181920
21222324252627
282930



Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.

Based on Astronomy Picture Of the Day

Publications with keywords: craters
Publications with words: craters
See also:
All publications on this topic >>