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Астронет: Астрономическая картинка дня Меркурий: Дега -- кратер с лучевой системой http://variable-stars.ru/db/msg/1162200/eng |
Credit & Copyright: Mariner 10 Project,
NASA
Explanation:
Like the Earth's Moon,
Mercury is scarred with craters
testifying to an intense bombardment during the
early history of
the Solar System.
In 1974,
the
Mariner 10 spacecraft
surveyed this innermost planet up close,
producing the only detailed images of its tortured surface.
In the above mosaic the bright rays
emanating from the 45 kilometer wide
Degas crater almost appear to be painted on.
The rays consist of light colored material blasted out during the
crater's formation.
Craters older than Degas are covered by the
ray material while younger craters are seen
superimposed on the rays.
Mercury's gravity and density
are about twice
that of Earth's Moon
so such bright
ray
craters on the lunar surface tend to be much larger.
NASA plans to launch MESSENGER
to the least explored terrestrial planet
in 2004.
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.