Saturn's New Moon: Polydeuces

Folks - FYI

Dave


saturn.jpl.nasa.gov/multimedia/images/im...ils.cfm?imageID=2183

Polydeuces
New Moon
June 28, 2006
Full-Res: PIA08209 < photojournal.jpl.nasa.gov/catalog/PIA08209> ;

This magnified view shows tiny Polydeuces, a moon that was discovered by the Cassini spacecraft and is a mere 3 kilometers (2 miles) across. Along with much larger Helene (32 kilometers, or 20 miles across), Polydeuces orbits Saturn at the same distance as large, icy Dione (1,126 kilometers, or 700 miles across).

Because this body was only recently discovered and is so small, scientists presently know precious little about it. Further observations by Cassini may yield additional insights about its nature and composition.

The image was taken with the Cassini spacecraft narrow-angle camera on May 22, 2006 at a distance of approximately 73,000 kilometers (45,000
miles) from Polydeuces and at a Sun-Polydeuces-spacecraft, or phase, angle of 41 degrees. The image was obtained using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers. Scale in the original image was 434 meters (1,423 feet) per pixel. The image has been magnified by a factor of four and contrast-enhanced to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit saturn.jpl.nasa.gov . The Cassini imaging team homepage is at ciclops.org .

Credit: NASA/JPL/Space Science Institute

Interesting article, and now to open another can of worms, maybe? :twisted:
When is a moon a moon, is every rock that orbits a planet a moon, this thing is only 3km across, what if they discovered a rock 100 meters across, is this a moon also ? or just a rock.

Good question! I don't know what the definition of a moon is but I have seen binary asteroid systems (one asteroid orbiting another) described as 'an asteroid with a moonlet'. In that case the 'moonlet' was a few tens of meters in diameter.

There was also an article recently describing an asteroid in a tenuous orbit around Earth as 'moons' (the orbit was not permanent and the 'moon' would eventually part company).

In the case of Saturn, it would have billions and billions of moons if you counted the particles in the rings...

Who cares what its called:

Rock or Moon?

"A rose by any other name would smell as sweet."
William Shakespeare.

Another problem I have thought about myself too, that one, and more so only around Saturn, as these tiny moons, could simply be large rocks escaped from the ring belts. Some even still orbit within the rings.

Did I not mention before how Hugh Grant turnd a Welsh hill into a Welsh mountain?
We'r'e into silly definitions again.
"Scientific" definition of a "rock" anybody?