Explanation:
What's that behind Titan? It's another of Saturn's moons:
Tethys.
The robotic
Cassini spacecraft orbiting Saturn
captured
the heavily cratered Tethys
slipping behind
Saturn's atmosphere-shrouded
Titan late last year.
The largest crater on
Tethys,
Odysseus, is easily visible on the distant moon.
Titan shows not only its thick and opaque orange lower atmosphere,
but also an unusual upper layer of
blue-tinted haze.
Tethys,
at about 2 million kilometers distant, was twice as far from
Cassini as was Titan when the
above image was taken.
In 2004, Cassini released the
Hyugens probe
which landed on Titan and provided humanity's
firstviews of the
surface of the Solar System's only known
lake-bearing moon.
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