posted on Jun, 16 2014 @ 05:11 AM
Discovered by William Henry Pickering on 17 March 1899 from photographic plates (and being the first satellite to be discovered photographically), it
is an irregular satellite of Saturn a little over 200 km in diameter.
Phoebe is truly an odd one among her "friends":
For several reasons, Phoebe is thought to be a captured object that does not share a joint origin with Saturn and the inner, "regular" satellites. It
orbits in a retrograde direction, opposite to the direction of Saturn's other major moons. Its overall density was determined by Cassini scientists to
be quite large for a moon of Saturn. The prevailing view is that Phoebe might have formed in the Kuiper Belt, far beyond the orbit of Saturn. It might
thus be a small cousin of the largest Kuiper Belt object, Pluto.
Most of Saturn's inner moons have very bright surfaces, but Phoebe's albedo is very low (0.06), slightly brighter than fresh asphalt or charcoal.
However, it is believed that underneath that dark surface, there is water ice.
NASA's spacecraft Cassini took some closeups of Phoebe on its way to the orbit around Saturn. These are the closest and most detailed images we have
of this moon. Since then, Cassini has been orbiting close to Saturn and never close enough to Phoebe to take such pictures again.
Here's a mosaic I made from Cassini's raw images
during that fly-by:
Full-sized version: www.pictureshack.us...
NASA article: saturn.jpl.nasa.gov...
Phil Plait's blog: www.slate.com...
managed to create colour mosaics of Phoebe, using data from
Cassini's Visual and Infrared Mapping Spectrometer (VIMS):
edit on 16-6-2014 by wildespace because: (no reason given)