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.
2010 March 10
Saturn's Moon Helene from Cassini Credit: NASA/JPL/SSI
Explanation:
What's happening on the surface of Saturn's moon Helene?
The moon was imaged in
unprecedented detail last week as the
robotic
Cassini spacecraft orbiting Saturn
swooped to
within
two Earth diameters of the diminutive moon.
Although conventional craters and hills appear, the above raw and unprocessed image also
shows terrain that appears unusually smooth and
streaked.
Planetary astronomers will be inspecting these detailed images of
Helene to glean clues about the origin and evolution of the 30-km across floating iceberg.
Helene is also unusual because it circles Saturn just ahead of the large moon
Dione, making it one of only four known Saturnian moons to occupy a gravitational well known as a stable
Lagrange point.
