APOD: Valles Marineris: The Grand Canyon... (2014 May 11)

[APOD Robot]

Valles Marineris: The Grand Canyon of Mars

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. 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.

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[dictostelium]

how does it not infill with dust?

[Nitpicker]

A great image. According to the details I found via the "above mosaic" link, the image is composed to represent the view from ~2500km altitude, such that only ~110° of the planet is visible.

(I imagine the dust blows in and out of the valley all the time, but never enough to fill it.)

[BDanielMayfield]

how does it not infill with dust?

(I imagine the dust blows in and out of the valley all the time, but never enough to fill it.)

Also, it's just plain huge. There very likely has been a lot of dust permantently collected over time inside Valles Marineris though, so the bedrock bottom of the thing could be even deeper.

[JohnD]

how does it not infill with dust?

With many assumptions, and using the volume of a tetrahedron to calculate, the Valles has a volume of 4.8 Million cubic kilometers.
Mars has a surface area of about 145 Million square kilometers, so that volume would demand the removal of 33 meters from the entire surface of the planet

It's like The Hitchhikers's Guide says about Space. The Valles is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space, and the Valles.

John

[jambo]

I wonder how it compares with Earth's rift valleys?

[BDanielMayfield]

Thinking about it's size, it makes our Grand Canyon look like a mere gully.

Erosion couldn't be it's casue. It's like the crust of Mars (think Mars' garment) ripped at the seam when it srinked.

[BDanielMayfield]

I wonder how it compares with Earth's rift valleys?

It is a rift valley. Compare it with, say, the Red Sea on Earth.

[Guest]

Funny, when I look at Valles Marineris, I see an asteroid grazing the surface of Mars and being sufficient to begin the Planet's most recent ELE. With enough velocity, I can see this being a viable theory.

[Psnarf]

In the large image, there are two features left of center that appear to be fractals.
It looks to me like something started from the left side, washed down left to right, and settled in that playa on the right edge.
You won't trick me into commenting on the giant 'H' above the far left side, nope, don't even see it, though it would be a nice touch if it were there.

[Chris Peterson]

Funny, when I look at Valles Marineris, I see an asteroid grazing the surface of Mars and being sufficient to begin the Planet's most recent ELE. With enough velocity, I can see this being a viable theory.

Really not possible. A grazing asteroid wouldn't cut a valley, it would produce an oval crater, and probably a chain of them. The result would look nothing like this. And anything large enough to "cut" a structure of this width and length would have melted the entire hemisphere.

It's certainly a tectonic and erosional structure of some sort.

[K.H.S.]

Really great photo of Mars !!!
And thanks for calculating the 33 feet of the surface necessary to fill in the Valles !!! I had been wondering about its total volume, but hadn't done the math yet !
It is so sad that Mainstream Astrophysics is continuing to remain willfully ignorant of the true forces in Nature that create such structures as the Valles Marineris, but that remains the case. Wake up Mainstream ! Your credibility is on the line here !

[Chris Peterson]

It is so sad that Mainstream Astrophysics is continuing to remain willfully ignorant of the true forces in Nature that create such structures as the Valles Marineris, but that remains the case. Wake up Mainstream ! Your credibility is on the line here !

I'm rather certain that our understanding of the tectonic and erosional processes that created this structure, as elucidated by planetary scientists, is reasonably accurate. The radar mapping of Mars reveals the actual crustal components in that hemisphere that are associated with the creation of the rift, and we have similar structures on the Earth (not the Grand Canyon, of course... that's just brought up for scale) that we can study more closely.

[BDanielMayfield]

In the large image, there are two features left of center that appear to be fractals.

There are many other fractal characteristics here too Psnarf. Note the numerous parallel running side "canyons" or valleys on both sides, but most notably on the north side of the main valley.

Bruce

[JohnD]

Funny, when I look at Valles Marineris, I see an asteroid grazing the surface of Mars and being sufficient to begin the Planet's most recent ELE. With enough velocity, I can see this being a viable theory.

We've had this conversation before, in particular about the "grooves on Phobos":
http://asterisk.apod.com/viewtopic.php? ... es#p191237

A glancing blow, an impact at a very low angle, does not produce a groove, but an impact crater that is as circular as a vertical one. There are many on the Moon, : http://the-moon.wikispaces.com/Oblique+Impact+Craters. If the angle is less than 12 degrees the crater may be more elliptic, but it's still a crater, not a gouged groove. There many elongated crater-like objects, for instance on Mars, this crater, http://www.sciencedaily.com/releases/20 ... 091502.htm
Those, including the Grooves on Phobos, are crater chains, lines of impacts from objects that have broken up into a "string of pearls" under the tidal forces of a gravity field, like Comet Shoemaker-Levy did before it impacted so spectacularly on Jupiter. http://www.space.com/19855-shoemaker-levy-9.html

John

[JohnD]

I wonder how it compares with Earth's rift valleys?

Jambo,
Why don't you do the math(s) yourself?
The dimensions of the Grand Canyon are given in the original caption.
The volume of a tetrahedron is Area of base (length x breadth) x depth x1/3. Easy-peasey!

That formula is a gross simplification, obviously, but probably ball-park, if giants played golf, and cut divots.

John

[JohnD]

Quote K.H.S,
"And thanks for calculating the 33 feet of the surface necessary to fill in the Valles !!!"

METERS!!!!!! Meters, boy!!!! Thirty three Meters of surface!!
Do keep up with the rest of the World.
John

[Chris Peterson]

I wonder how it compares with Earth's rift valleys?

Jambo,
Why don't you do the math(s) yourself?
The dimensions of the Grand Canyon are given in the original caption.
The volume of a tetrahedron is Area of base (length x breadth) x depth x1/3. Easy-peasey!

That formula is a gross simplification, obviously, but probably ball-park, if giants played golf, and cut divots.

Or, you could Google it and find one of the papers on the subject (like this one) that have looked at the GIS data created by radar mapping. This also serves to show the value of back-of-the-envelope calculations like yours. Using a trivial and apparently reasonable calculation, you came up with a volume of 4.8 million cubic kilometers. People analyzing the actual surface data came up with 3.6-3.9 million cubic kilometers. Not bad at all.

[JohnD]

Thank you, kind Sir!
(Tips tea cup to the Astronomer)
Didn't they do well?
28 meters, not 33.

OK boys, you can stop digging!
John

[Boomer12k]

An AWESOME image for so many photographs to be knitted together in a mosaic....I thought I was looking at ONE PHOTO newly taken....GREAT JOB!!!!

I have read where it was caused by the planet cooling...

But I favor the Ancient Astronaut theory that a Giant SPACE Battleship crash landed on its SIDE.....


:---[===] *

[rwlott]

I wonder how it compares with Earth's rift valleys?

My first thought was: How does it compare to the Marianas Trench on Earth? Wikipedia says that this geologic structure in the Western Pacific Ocean is almost as long (at 2,550 km) and deeper (10.9 km at its maximum depth), though not nearly as wide (only 69 km on average). If our planet were oceanless then the Marianas Trench would make for a similarly striking image.

[jambo]

RE rift valley--my first thought also was of the East African one; then I wondered about some of the oceanic trenches, but found those are related to collision/subduction tectonics. The mid-oceanic rifts would also compare to the Martian one; however in a quick search, I didn't find any size comparisons. The other question I'm sure someone can answer is if this Mars picture represents the rift as relatively equatorial, as several of Earth's rifts are more aligned pole to pole.

[Sinan İpek]

Does anybody believe NASA's project about sending people to Mars to settle there and never return where there is no oxygene and water... just a very very cold desert and no one but a few people?

[geckzilla]

Does anybody believe NASA's project about sending people to Mars to settle there and never return where there is no oxygene and water... just a very very cold desert and no one but a few people?

Do you mean this? Mars One?
It's not NASA's project, but yeah, I think they will probably succeed in some manner. I also think the people involved are in for a lot of heartbreak, but that remains to be seen...

[Frankcheck]

Could it be the result of huge asteroid detonation passing really close to mars? It looks like!