Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://www.sai.msu.su/apod/ap000829.html
Дата изменения: Unknown Дата индексирования: Mon Oct 1 23:14:39 2012 Кодировка: Поисковые слова: ancient observatory |
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
![]() Credit: NEAR Project, JHU APL, NASA |
Explanation: From fifty kilometers above asteroid Eros, the surface inside one of its largest craters appears covered with an unusual substance: regolith. The thickness and composition of the surface dust that is regolith remains a topic of much research. Much of the regolith on 433 Eros was probably created by numerous small impacts during its long history. In this representative-color view taken by the robot spacecraft NEAR-SHOEMAKER currently orbiting Eros, brown areas indicate regolith that has been chemically altered by exposure to the solar wind during micrometeorite impacts. White areas are thought to have undergone relatively less exposure. The boulders visible inside the crater appear brown, indicating either that they are old enough to have a surface itself tanned by the solar wind, or that they have somehow become covered with some dark surface regolith. |
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell (USRA)
NASA Technical Rep.:
Jay Norris.
Specific rights apply.
A service of:
LHEA at
NASA/GSFC
&
Michigan Tech. U.