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from Thunderbolts Website
Credit:
NASA/JPL/Space Science Institute
Phoebe is also as black as night, making
it one of the darkest objects in the Solar System. The temperature
on Phoebe is estimated to be around 200 below zero Celsius.
As the then named Cassini-Huygens spacecraft entered Saturn space, it passed 2000 kilometers from the moon’s surface on June 11, 2004 making it the first and only time that Cassini came close to Phoebe.
Since its orbit is almost 13 million kilometers from Saturn, Cassini
will be unable to boost out to that distance. The farthest it was
scheduled to travel is to the orbit of
Iapetus, about 3 million
kilometers out.
In previous Pictures of the Day, the question of why asteroids with large craters were not destroyed by impacts from putative chunks of fast-moving rock was asked.
The same question can be asked about Phoebe: why was it not blown apart by whatever “impact” events excavated its craters (below images).
Phoebe’s dark surface is reminiscent of
Halley’s comet, another scorched looking black body, as well as
comet Wild 2 (below image). The heavily cratered terrain on all three objects was
contrary to the expectations of NASA observers.
According to a recent press release, NASA scientists describe Phoebe as “very strange” and probably a captured moon, rather than having formed along with its parent planet in a so-called “primordial cloud”.
Said Peter Thomas of Cornell University:
Images from the Cassini spacecraft depict a moon that has features like those found on other moons described in recent articles.
Some are similar to features on the Martian moon Phobos.
The crater rims have alternating striations, with steep gullies running down one side and hard edges that appear as if they were cut into the rock and ice.
What appear to be rounded boulders lie
inside some of the craters as well as in the faces of the crater
walls.
A closer examination (below image) casts doubt on the notion that the largest crater could have been created by an object smashing into Phoebe. The alternative - formation by plasma discharge - is well supported.
The most obvious evidence is the
spiral-shaped crater rim and the steeply carved cliffs. These are
not features expected under an impact hypothesis.
The shallow craters, the overlapping rims
and the lack of impact debris are also important considerations in
the theory of electrical effects, not only on Phoebe but the rest of
Saturn’s moons.
By thinking only in terms of meteor impacts, landslides and other familiar geological forces, NASA is ignoring the one possibility that makes all the disparate features we see cohesive:
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