Loop I in the Northern Sky
Explanation:
One of the largest coherent structures
on the sky is known simply as
Loop I and can best be seen in
radio and
X-ray maps.
Spanning over 100 degrees, part of
Loop I appears so prominent in
northern sky maps that it is known as the
North Polar Spur (NPS).
Loop I,
shown above in
X-ray light,
is a thin bubble of gas about 700 light-years across
with a center located only about 400 light-years away.
Surprisingly, the cause of this immense structure
is still debated, but is possibly related to expanding
gas from a million-year old
supernova.
Loop I gas is impacting the nearby
Aquila Rift
molecular cloud,
and may create relatively dense fragments of the local
interstellar medium.
Were our Sun to pass through one of these fragments
in the next few million years, it
might affect Earth's climate.
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.
