View a MOV animation, or view the stills below for a summary of the story. (19.5 mB MOV file)
You are here! The sun's position in the Milky Way.
The sun is located in an outer region of the Milky Way galaxy, a huge pinwheel of
some 200 billion stars. In the "empty" regions between the stars lies a tenuous
component of gas and interstellar dust known to astronomers as the INTERSTELLAR MEDIUM.
The region studied previously.
In the 1970s, NASA flew a satellite known as Copernicus. This satellite looked
at the same range of light as FUSE, but with much lower sensitivity. Hence, it could
only be used to observe relatively bright stars in the region right around the sun
(green region in diagram). Copernicus demonstrated the need for a much more
powerful telescope to observe far-ultraviolet light, and that telescope is FUSE!
FUSE views the Milky Way.
Unlike Copernicus, FUSE will be able to see stars and nebulae in nearby spiral
arms and throughout our galaxy. FUSE is 10,000 times more sensitive than Copernicus,
and will be able to study HUNDREDS of sight-lines through the interstellar medium,
building up a detailed picture of the temperature structure and composition
of the gas and dust in our galaxy.
Beyond the Milky Way.
FUSE will also be able to observe the hottest stars in nearby galaxies (for comparison
with the Milky Way's stars), and will even be able to observe active galaxies and
quasars out to several billion light years away!