How do planets form? Astronomers are finding
out by studying one of the most interesting of all astronomical
nebulae known, the Great Nebula in Orion.
Insets to above mosaic
show several planetary systems in
formation. The bottom left insert shows the relative size of
our own Solar System. The Orion Nebula
contains many stellar nurseries. These nurseries contain hydrogen
gas, hot young stars, proplyds, and
stellar jets spewing material at
high speeds. Much of the filamentary structure visible in this
image are actually shock waves
- fronts where fast moving material encounters slow moving gas.
Some shock waves are visible near one of the bright stars in the
lower left of the picture. The Orion Nebula
is located in the same spiral arm of our Galaxy
as is our Sun.
On This Day in Space History
On December 7, 1972, Apollo 17 astronauts captured "The Blue Marble," one of the most reproduced photographs in history.