Orion's Horsehead Nebula
Explanation:
The
Horsehead Nebula
is one of the most famous nebulae on the sky. It is visible
as the black indentation to the red emission
nebula
seen just to the right of center of the above photograph. The
bright star near the center 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.
