Astronomy Picture of the Day 8-27-02

NASA ^ | 8-27-02 | 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 August 27

Valles Marineris: The Grand Canyon of Mars
Credit: Viking Project, USGS, NASA

Explanation: The largest canyon in the Solar System cuts a wide swath across the face of Mars. Named Valles Marineris, the grand valley extends over 3,000 kilometers long, spans as much as 600 kilometers across, and delves as much as 8 kilometers deep. By comparison, the Earth's Grand Canyon in Arizona, USA is 800 kilometers long, 30 kilometers across, and 1.8 kilometers deep. The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled. Recently, several geologic processes have been identified in the canyon. The above mosaic was created from over 100 images of Mars taken by Viking Orbiters in the 1970s.

[petuniasevan]

Astronomy Fun Fact:

Those prominent round brown spots on the left side of the image are ancient volcanos.
One Martian volcano (Olympus Mons) is the biggest volcano in the Solar System.

Nice to see they're still getting mileage out of archived Viking images.

More Mars missions! We need more Mars missions!

Get on the list!

[petuniasevan]

I wouldn't have put this up until after 5 AM Central, but I don't trust the "15 minute" downtime estimate.
Nothing ever runs THAT smoothly!

[RightWhale]

At some point something really major happened to Mars. The surface layer, the crust of one hemisphere is missing. The big volcanos are all clustered together and are opposite a big hole. And there is the giant rift valley on a planet with little tectonic activity at present. The idea that the asteroids are the remains of an exploded planet orbiting the sun somewhat beyond Mar's orbit is an old idea but still hasn't faded away.

Van Flandern and Hoagland have pointed out all this and more, including the fact that the huge water discoveries seem to be located in tidal mounds.

Who knows what may yet be discovered on Mars. We should go there, not just with robot ships, but manned expeditions and start digging in for a permanent base.

[sleavelessinseattle]

More Mars missions! We need more Mars missions!

Go P7 GO!!!! Wow that would be fun to fly through or have big dune buggy races through...I want to live forever everytime I think about the wonders of the universe...so much to see...APOD RULES!

[Freedom2specul8]

That is so awesome..I can't imagine how large they are...

[Freedom2specul8]

The details are incredible..I love the close up.

[WSGilcrest]

.

[sistergoldenhair]

Nice.

[2Trievers]

Awesome pics! Thanks 'tunia! &;-)

[MeekOneGOP]

What a picture. Thanks!

[BossyRoofer]

What a great picture! You know it looks like an object skiped off the surface from the shape of the canyon!

[CJ Wolf]

I can see that, too now that you mention it. Looks like a big glancing cut in the surface.

[GodsLittleOne]

wow

[Savage Beast]

Maybe a sharp piece of exploding planet grazed the side of Mars as it sailed into outer space.