Explanation:
This gorgeous
image of Orion shows off the constellation's
young stars and cosmic clouds of hydrogen gas and dust.
Made with a film camera tracking the stars on November 11,
the exposure lasted some 40 minutes.
It includes the Great Orion Nebula
(near center),
a string of well-known nebulae leading upwards
to Orion's three belt stars,
and the large semi-circular arc known as
Barnard's Loop that seems
to end at the bottom right,
next to bluish supergiant star Rigel.
Serendipitously, the picture also recorded a bright, comet-shaped cloud
not known to share the sky with
Orion's famous stars and nebulae.
Also spotted
by other skywatchers, the mystery cloud was quickly
recognized as a fuel dump from a booster
rocket used
to place a satellite in
geosynchronous orbit.
Reflecting sunlight, the fuel dump plume begins on the west (right)
side of the star field
and expands as it slowly drifts eastward and fades
during the time exposure, creating the
wedge-shaped streak.
