The Hubble
Space Telescope captures the most detailed image ever taken of a spiral galaxy.
Astronomers
stitched together 51 separate images from Hubble - with a few other details
from ground-based instruments - to build this mosaic of Messier 101, also known
as the Pinwheel Galaxy. At an impressive 16,000 by 12,000 pixels, the image is
the largest and most detailed ever caught of a spiral galaxy.
The
Pinwheel Galaxy is about 170,000 light-years wide, almost twice the diameter of
our own Milky Way, and is estimated to contain at least one trillion stars. Astronomers
believe that perhaps 100 billion of those stars may be similar to our Sun, and
millions of individual objects can be picked from this image.
The galaxy
itself sits about 25 million light-years away toward the northern constellation
Ursa Major. The light that reached Earth to build this portrait left the
Pinwheel Galaxy during our planet's Miocene Period, when the first mastodon appeared
and mammals were flourishing.
-- SPACE.com Staff
Credit: ESA/NASA/STScI
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