Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
January 25, 1997
Explanation: The Whirlpool Galaxy is a classic spiral galaxy.
At only 15 million light years distant, M51,
also catalogued as NGC 5194,
is one of the brighter and more picturesque galaxies
on the sky. The smaller galaxy appearing here above and to the
right is also well behind M51,
as can be inferred by the dust in M51's
spiral arm blocking light from this smaller galaxy. Astronomers
speculate that M51's spiral structure
is primarily due to it's gravitational interaction with this smaller
Authors & editors:
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.