We see the brignt band of the Milky Way Galaxy spanning the bottom of this image,
with the Rho Ophiuchi dust cloud floating above. This large swath of infrared sky
is 60 degrees in width, and the blue, green, and red colors correspond to the
12, 60, and 100 micron bands observed by the Infrared Astronomical Satellite (IRAS).
The brightest emission arises from the very distant clouds of dust that fill the
disk of our Galaxy much of it many thousands of light years distant. The brightest bulge
just left of middle is the very core of the Milky Way, in the direction of the constellation
Sagitarius.
The cloud of interstellar dust looming above the Galactic plane is a large
region of star formation around the star known as Rho Ophiuchi. This cloud
is much closer to us, just under 500 light years away. The cloud
glows brightly in the infrared light as
numerous new stars forming within the cloud heat the dust which
surrounds them. The greenish glow to the lower right of the Rho
Ophiuchi cloud comes from dust surrounding and heated by the hot
young binary star Sigma Scorpii. The filaments and wisps extending
out from these two clouds are due to tenuous interstellar dust
concentrations probably associated with the central clouds.
Image credits: IRAS/MONTAGE/R. Hurt