Astronomy Picture of the Day 5-19-02

NASA ^ | 5-19-02 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 May 19

Saturn's Moon Tethys
Credit: Voyager Project, NASA; Copyright: (digital w/colortable): Calvin J. Hamilton

Explanation: Tethys is one of the larger and closer moons of Saturn. It was visited by both Voyager spacecraft - Voyager 1 in November 1980 and by Voyager 2 in August 1981. Tethys is now known to be composed almost completely of water ice. Tethys shows a large impact crater that nearly circles the planet. That the impact that caused this crater did not disrupt the moon is taken as evidence that Tethys was not completely frozen in its past. Two smaller moons, Telesto and Calypso, orbit Saturn just ahead of and behind Tethys. Giovanni Cassini discovered Tethys in 1684. In 1997, NASA launched a spacecraft named Cassini to Saturn that will arrive in 2004.

[petuniasevan]

When we finally send manned (return) missions far afield, icy moons like Tethys will be great refueling stops.
Water provides both fuel and oxygen for the voyage home...

Get on the APOD PING list!

[petuniasevan]

APOD PING!

[sleavelessinseattle]

Crash that puppy into Mars and set us all up with a big ole snowpark!!!Terraforming will be proof that humanity is not a fluke...Until we prove that we can diversify our species to more than one gravity well, we're clever monkeys...

[2Trievers]

Just be careful out there ... danger lurks behind every crater ...

[petuniasevan]

"Where's the KABOOM? There's supposed to be an Earth-shattering KABOOM!"

[petuniasevan]

Crash that puppy into Mars and set us all up with a big ole snowpark

You must be thinking of icy moonlets or comets. This moon of Saturn is 1500 miles across.

Crash that puppy into Mars and set us up with a molten slag heap strung out in orbit where Mars USED to be!

[aomagrat]

That's a mighty big snowball you got there. Calvin would be proud.

[Hellmouth]

Looks ike a cookie....

[Hellmouth]

Or the fossilized top hjalf of a hamburger bun....

[sleavelessinseattle]

Well I didn't say how FAST to crash it into Mars! Point taken though... If you put it into a grazing orbit, you could use Atmospheric braking to siphon off some water each time it bumped up against Mars' thin atmosphere...I'm just looking for a retirement community with a view; Counter rotating moons and all...LOL!