Page 2 of 3

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 7:18 pm
by neufer
bystander wrote:
geckzilla wrote:
I thought the flamingo was a reference to the teaser title for tomorrow's APOD, flappy sky.
But I don't know why he would post about tomorrow's APOD in today's thread.
When has neufer needed a reason for anything?
Indeed! In fact, if at anything time you think that you understand my posts that is probably cause for concern.

Image

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 7:54 pm
by neufer
Chris Peterson wrote:
since "old timers" learned their 'rithmatic without calculators, most can do a bit of simple reckoning in their heads, no?
Kilometers times two divided by three will get you in the miles ballpark.
Dividing by three in one's head (or on paper) can be tricky at times.

Try: kilometers times six and then shift the decimal point.[/quote]
300,000 km/s => 1,800,000 => 180,000 m/s

For miles to kilometers: miles doubled 4 times and then shift the decimal point:
186,000 m/s => 372,000 => 744,000 => 1,488,000 => 2,976,000 => 297,600 km/s

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 8:05 pm
by neufer
kaigun wrote:
Speaking of miles and kilometers, the text for the photo says the canyon is 3000km long, while the JPL video linked to says the canyon is 3000 miles long (NY to LA). Which is correct, and didn't we lose one of the Martian probes because of English unit/metric unit foul-up?
The APOD should probably read 4000 km long.
http://astrogeology.usgs.gov/Projects/VallesMarineris/ wrote:
<<The Valles Marineris ... is about 4000 km long, and, if on earth, would extend all the way across the United States. The central individual troughs, generally 50 to 100 km wide, merge into a depression as much as 600 km wide. In places the canyon floor reaches a depth of 10 km, 6 to 7 times deeper than the Grand Canyon.>>

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 8:23 pm
by dougettinger
What caused this so-called 3000 km crack ? The explanation of the APOD claims this is a crack due to crustal shrinkage; I would think there should be other cracks as well. Another claim is that a huge asteroid side-swiped Mars and then went on its merry way. A "side-swipe" this large is too hard to believe.

After careful examination I believe it was an asteroid strike in the center where the widest portion of the valley exists. The crust was very fragile and cracked due to the impact. The Martian mantle had already cooled sufficiently that it did not ooze outward on top of the crust. The cooled mantle would compare to a boiled egg as opposed to a fresh egg. The radial filaments of the blast have been long eroded and/or hidden by sandstorms.

Please do not consult any talking flamingos; I am pursuing some highly opinionated views regarding my hypothesis. Thank you.

3/27/2011

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 8:38 pm
by Ron Stewart
Should the topographic morphing processes on Mars be called areologic and not geologic?

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 8:44 pm
by dougettinger
Ron, I am only asking for your opinion and use any kind of logic you wish.

3/27/2011

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 9:36 pm
by nonprophet
WildGuruLarry wrote:That is a crazy thought. The problem is that such a collision is way more violent than you seem to assume. For example, check out this simulation
Thanks for your reply.
Am I not allowed to posit a collision which is less violent than assumed by the creators of that animation? We don't know if they assumed two bodies of equal hardness, and we don't know if the animation accurately shows the result of a "scraping" impact rather than a more direct hit. A simple game of billiards demonstrates that the amount of energy transferred between objects is highly variable depending on several factors, with resulting vast differences in effect.

nonprophet
South Dakota

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 10:21 pm
by dougettinger
The nonprophet's hypothesis also states that the collisional material accretes to become the Earth's moon. Martian gravity field and the necessary momentum and energy changes work against any substantial material moving toward the Earth's orbit. Any transfer of water should either be totally dispernsed or fall back to Mars or the impactor body.

But another body glancing Mars has been suggested.

3/27/2011

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 10:22 pm
by neufer

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 11:42 pm
by bbonomi
Instead of comparing it to surface features, why not look to the Mariana Trench in the Pacific? More comparable in size; possibly in origin. We think about plate tectonics here so maybe Valles Marineris is the edge of a tectonic plate that existed when Mars still had a molten core -- it wouldn't be a "split" caused by the cooling but rather the edge of an existing geological feature that solidified as it cooled?

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Sun Mar 27, 2011 11:51 pm
by garry
If you look at the picture closely, you will see that at the start and the end of the "Crack" there are circular formations, like craters. Closer images of Valles Marineris shows so many anomalies that do not hold it being some type of "Crack" And besides, when does any crack end up with uniform serrated edges? Water used to be the the scientific reason for the valley but that was just ridiculous. What's next?

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 1:34 am
by NoelC
Sam wrote:A greater number of Lesser Flamingos
Wow, that scored almost a 0.6 of 1.0 on the Neuferism scale. I'm not sure anyone besides Neufer has scored that high before.

Thanks, Owlice. Not having the original image side by side with the Flamingo I didn't see the correllation before either.

Anyone besides me see the trumpet on wheels (which are of course needed for such a big trumpet).

No one's asked about the bites out of the Martian disk at the bottom-right. Those are from the Tyranosaur chasing the Flamingo, must be.

-Noel

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 3:28 am
by aristata
One can almost see the little green people down there. A very awesome photo.

But I write because I just switched to a Win 7 machine and have learned that APOD is not fully supported in that OS. Is this true, or is there any help for this situation? Many thanks,

thad

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 4:02 am
by moonstruck
Thanks Owlice I will do that. I've been using my cell phone for calculating unit conversion.
Also thanks to Chris. This old timer didn't know bout that. If I can find my crayons I'll write that down. Just kidding, thanks a bunch.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 4:45 am
by ThinkerEmeritus
Wouldn't the Izu-Bonin-Mariana Arc be a better terrestrial comparison than the Grand Canyon? After all, the water covering the Earth shouldn't count against the Earth in comparisons with Mars.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 5:08 am
by Chris Peterson
aristata wrote:But I write because I just switched to a Win 7 machine and have learned that APOD is not fully supported in that OS. Is this true, or is there any help for this situation?
APOD is a website. As such, it can be viewed by any compliant browser, running on any operating system that can support a browser. That includes Windows 7.

Are you seeing APOD via a browser, or perhaps using some third-party tool which displays its contents, creates wallpaper, or something along those lines? If so, it is perfectly possible for such an app to work only with a particular OS.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 6:52 am
by neufer
bbonomi wrote:
Instead of comparing it to surface features, why not look to the Mariana Trench in the Pacific? More comparable in size; possibly in origin. We think about plate tectonics here so maybe Valles Marineris is the edge of a tectonic plate that existed when Mars still had a molten core -- it wouldn't be a "split" caused by the cooling but rather the edge of an existing geological feature that solidified as it cooled?
ThinkerEmeritus wrote:
Wouldn't the Izu-Bonin-Mariana Arc be a better terrestrial comparison than the Grand Canyon? After all, the water covering the Earth shouldn't count against the Earth in comparisons with Mars.
Valles Marineris, the Grand Canyon and the Great Rift in Africa are all depressions in a highlands region.

The Mariana Trench is a depression in a lowlands region.

It would be apples & oranges.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 9:31 am
by nonprophet
dougettinger wrote:The nonprophet's hypothesis also states that the collisional material accretes to become the Earth's moon. Martian gravity field and the necessary momentum and energy changes work against any substantial material moving toward the Earth's orbit. Any transfer of water should either be totally dispernsed or fall back to Mars or the impactor body.

But another body glancing Mars has been suggested.

3/27/2011
I never acquired the tools and knowledge needed to work out this sort of thing for myself, so I appreciate your help. I understand what you're saying and am satisfied that it's a good answer. Yes, I noticed while looking into this that it's been suggested another body's glancing impact with Mars could explain the Valles Marineris.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 10:03 am
by aristata
Chris Peterson wrote:
aristata wrote:But I write because I just switched to a Win 7 machine and have learned that APOD is not fully supported in that OS. Is this true, or is there any help for this situation?
APOD is a website. As such, it can be viewed by any compliant browser, running on any operating system that can support a browser. That includes Windows 7.

Are you seeing APOD via a browser, or perhaps using some third-party tool which displays its contents, creates wallpaper, or something along those lines? If so, it is perfectly possible for such an app to work only with a particular OS.
APOD appeared daily on my desktop, a different shot each day of course, that I often would click on to bring up in my browser. With Win 7 it does not update and there is no accompanying explanation. Now I will have to bookmark it. If we can put a man on the moon, why can't I continue to get APOD on my desktop every day?

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 10:51 am
by Indigo_Sunrise
kaigun wrote:Speaking of miles and kilometers, the text for the photo says the canyon is 3000km long, while the JPL video linked to says the canyon is 3000 miles long (NY to LA). Which is correct, and didn't we lose one of the Martian probes because of English unit/metric unit foul-up?

Has this been answered?

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 11:58 am
by geckzilla

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 12:03 pm
by geckzilla
Indigo_Sunrise wrote:
kaigun wrote:Speaking of miles and kilometers, the text for the photo says the canyon is 3000km long, while the JPL video linked to says the canyon is 3000 miles long (NY to LA). Which is correct, and didn't we lose one of the Martian probes because of English unit/metric unit foul-up?

Has this been answered?
A quick Google search indicates that it is approximately 4000 kilometers long or 2500 miles long.

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 12:04 pm
by geckzilla
aristata wrote:
Chris Peterson wrote:
aristata wrote:But I write because I just switched to a Win 7 machine and have learned that APOD is not fully supported in that OS. Is this true, or is there any help for this situation?
APOD is a website. As such, it can be viewed by any compliant browser, running on any operating system that can support a browser. That includes Windows 7.

Are you seeing APOD via a browser, or perhaps using some third-party tool which displays its contents, creates wallpaper, or something along those lines? If so, it is perfectly possible for such an app to work only with a particular OS.
APOD appeared daily on my desktop, a different shot each day of course, that I often would click on to bring up in my browser. With Win 7 it does not update and there is no accompanying explanation. Now I will have to bookmark it. If we can put a man on the moon, why can't I continue to get APOD on my desktop every day?
Because APOD still runs on tech that was used back when they put that man on the moon. I'm afraid it's incompatible with your newer tech.

(I'm actually not joking, here)

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 12:18 pm
by Indigo_Sunrise
geckzilla wrote:
Indigo_Sunrise wrote:
kaigun wrote:Speaking of miles and kilometers, the text for the photo says the canyon is 3000km long, while the JPL video linked to says the canyon is 3000 miles long (NY to LA). Which is correct, and didn't we lose one of the Martian probes because of English unit/metric unit foul-up?

Has this been answered?
A quick Google search indicates that it is approximately 4000 kilometers long or 2500 miles long.


Thank you, googlezilla! Oooops! I mean, geckzilla!

:lol:

Re: APOD: Valles Marineris: The Grand Canyon... (2011 Mar 27

Posted: Mon Mar 28, 2011 12:37 pm
by bystander
geckzilla wrote:APOD appeared daily on my desktop, a different shot each day of course, that I often would click on to bring up in my browser. With Win 7 it does not update and there is no accompanying explanation. Now I will have to bookmark it. If we can put a man on the moon, why can't I continue to get APOD on my desktop every day?
Because APOD still runs on tech that was used back when they put that man on the moon. I'm afraid it's incompatible with your newer tech.

(I'm actually not joking, here)[/quote]
APOD works fine, it his widget that doesn't work.