Moon AND Stars
Credit & Copyright: T.A. Rector,
I.P. Dell'Antonio,
NOAO,
AURA,
NSF
Explanation:
Here's something you don't see too often ... a detailed picture of the
full Moon surrounded by a rich field of background stars.
It's true that bright moonlight scattered by the atmosphere tends to
mask faint stars, but pictures of the
sunlit portion
of the Moon made
with
earthbound telescopes
or even with cameras on the
lunar surface often
fail to show any background
stars at all.
Why? Because the exposure times are too short.
Very short exposures, lasting fractions of a second, are required to
accurately
record
an image of the bright lunar surface.
But the background stars (and galaxies!) such as those visible above
are much fainter and need exposures lasting minutes to hours which
would seriously
overexpose
the surface of the Moon.
So, of course
this stunning view
really is a combination of two digital images --
a short exposure, registering the exquisite lunar
surface details
at full Moon, superposed on
a separate very long exposure, made with
the Moon absent from the star field.
The final representation
of
Moon and background stars is very
dramatic, even though it could not have been captured in a single
exposure.
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.
