Astronomy Picture of the Day |
APOD: 2005 October 4 - The Milky Way in Stars and Dust
Explanation:
The disk of our Milky Way Galaxy is home to hot nebulae, cold dust, and billions of stars.
This disk can be seen from a dark location on Earth as a
band of diffuse light
across the sky.
This band crosses the sky in dramatic fashion in the
above series of wide angle sky exposures from
Chile.
The deepness of the exposures also brings to light a vast network of complex
dust filaments.
Dust is so plentiful that it obscures our
Galaxy's centre in visible light,
hiding its true direction until
discovered by other means early last century.
The Galactic Centre, though, is
visible above as the thickest part of the disk.
The diffuse glow comes from billions of older, fainter stars like
our Sun,
which are typically much older than the dust or any of the nebulae.
One particularly photogenic area of darkness is the
Pipe Nebula visible above the Galactic Centre.
Dark dust is not the
dark matter than dominates our Galaxy -- that
dark matter remains in a form
yet unknown.
APOD: 2000 January 30 - The Milky Way in Infrared
Explanation:
At night, from a dark location, part of the clear sky looks
milky.
This unusual swath of dim light is generally visible during
any month and from any location.
Until the invention of the telescope,
nobody really knew what the "Milky Way" was.
About 300 years ago telescopes caused a startling revelation: the Milky Way was made of
stars.
Only 70 years ago,
more powerful telescopes
brought the further revelation that the
Milky Way is only one galaxy among many.
Now telescopes in space allow yet deeper understanding.
The
above picture was taken by the
COBE satellite
and shows the plane of our Galaxy in infrared light. The thin disk of our home
spiral galaxy
is clearly apparent, with stars appearing white and
interstellar dust appearing red.
APOD: 2005 June 5 - A Milky Way Band
Explanation:
Most bright stars in our
Milky Way Galaxy reside in a disk.
Since our Sun also resides in this disk, these stars
appear to us as a
diffuse band that circles the sky.
The above panorama of a
northern band of the
Milky Way's disk covers 90 degrees and is a
digitally created mosaic of several independent exposures.
Scrolling right will display the rest of this spectacular picture.
Visible are many
bright stars,
dark dust lanes,
red emission nebulae,
blue reflection nebulae, and
clusters of stars.
In addition to all this matter that we can see,
astronomers suspect there exists even more
dark matter that we cannot see.
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:
EUD at
NASA /
GSFC
& Michigan Tech. U.