Orions Horsehead Nebula
Explanation:
The
Horsehead Nebula
is one of the most famous nebulae on the sky.
It is visible as the dark indentation to the red emission
nebula
seen above and to the right of center in the
above photograph.
The bright star on the left is located in the
belt of the familiar constellation of
Orion.
The
horse-head
feature is dark because it is really an opaque
dust cloud which lies in
front of the bright red
emission nebula.
Like clouds in
Earth's atmosphere, this cosmic cloud has assumed a
recognizable shape by chance.
After many thousands of years, the internal motions of the cloud
will alter its appearance.
The emission
nebula's red color is caused by
electrons recombining with
protons to form
hydrogen atoms.
Also visible in the picture are blue reflection
nebulae,
which preferentially
reflect the blue light from
nearby stars.
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.
