Astronomy Picture of the Day

NASA ^ | 9/9/07 | NASA

[sig226]

The Great Basin on Saturn's Tethys
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: Some moons wouldn't survive the collision. Tethys, one of Saturn's larger moons at about 1000 kilometers in diameter, survived the collision, but sports today the expansive impact crater Odysseus. Sometimes called the Great Basin, Odysseus occurs on the leading hemisphere of Tethys and shows its great age by the relative amount of smaller craters that occur inside its towering walls. Another large crater, Melanthius, is visible near the moon's terminator. The density of Tethys is similar to water-ice. The above digitally enhanced image was captured in July by the robot Cassini spacecraft in orbit around Saturn as it swooped past the giant ice ball.

[sig226]

[Malsua]

have to say it.

That’s no moon, it’s a space station.

[starfish923]

Melanthius was a noted Greek painter of the 4th century BC. He belonged to the school of Sicyon, which was noted for fine drawing.

Melanthius was also one of the minor characters who plays an important role in the context of Homer's epic poem, The Odyssey. He is a disloyal goatherd, treating Odysseus with contempt when Odysseus meets him by the fountain dedicated to the nymphs with Eumaeus, disguised as a beggar. Melanthius also mocks him at the palace in Ithaca and he meets his end at the hands of Odysseus. Melanthius helps the suitors and betrays Odysseus. When Odysseus wins, Odysseus seizes Melanthius, takes him to a court, chops Melanthius' nose and ears off with a sword, pulls off Melanthius' genitals to feed to the dogs, and chops Melanthius' hands and feet off.

Ouch.
I wonder why this basin was named after him, whether the painter or the betrayer of Odysseus.

[Bean Counter]

So Odysseus was Muslim???...

[dragonblustar]

[RightWhale]

The density of Tethys is similar to water-ice.

This might be a clue. While Nebraska and the moon are short of water, plenty of water, more than we can use, and oil too, is right there and obviously we have the tech to get there.

[burzum]

Talking about moons, Cassini is going to flyby Iapetus at 800 miles tomorrow. Iapetus is perhaps the coolest moon in the solar system. One side is as bright as fresh snow and the other is as dark as tar. It also has a 13 km high ridge along its equator and it orbits Saturn with a high orbital inclination.

[burzum]

Oh, and Iapetus only has a mean density of 1.0830 g/cm³ meaning that it is mostly composed of ice! It is an iceball with a 735 km radius!