NASA Rover Rolls Off Lander and Onto Mars

AP via Yahoo ^ | Jan. 15, 2004 | Andrew Bridges

[GalaxieFiveHundred]

Great, just freakin' great! Now they'll send us one of their rovers and our goose is cooked!

[Dead Corpse]

Either that is some EXTREMELY fine sand, or that stuff is WET. You can see some clumping along the edges of the tire tread marks. Like what you would get driving a truck with mudders on it through a damp patch of dirt.

Or is that wishful thinking?

[humblegunner]

And look, Queen Sheila was right.. there is a flag on Mars..

[RightWhale]

If they should get one of those dust storms or a dust devil, they could go back to look at old wheel tracks and see what the fresh dust did.

[Lokibob]

That was a concern of mine. What if a windstorm comes up and tips rover over? That would be the end of the mission.

On the plus side, due to the low air pressure on Mars, a 40 mph wind has a lot different affect on Mars than on Earth. I believe I read that it was 1/6th the effect which would mean a 40 MPH wind on Mars equals a 6MPH earth effect.

[RightWhale]

Not sure about this, but heard of Martian wind up to 300 mph. Could that get under the Rover's solar panel and lift the cart?

[Lokibob]

IF the martian wind hit 300 mph and IF my 1/6 force is correct, that would be an effective wind of 50 MPH on earth. I have no idea if a 50 mph wind would tip the rover over.

Going to go look now about that 1/6th pressure.

[Lokibob]

In passing I just found this picture taken in 2001:

 

Mars Global Surveyor
Mars Orbiter Camera

A Mid-Summer's Dust Devil

MGS MOC Release No. MOC2-281, 24 May 2001

| With Annotation | Without Annotation |

One objective for the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) in the Extended Mission is to continue looking for changes and dynamic events taking place on the red planet. The feature shown here elicited gasps of exitement among the MOC Operations Staff when it was received in early April 2001.

The feature is a dust devil. Dust devils are spinning, columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes. Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars. When this dust devil was spied in Amazonis Planitia on April 10th, the MOC was looking straight down. Usually when the camera is looking down the dust devil will appear as a circular, fuzzy patch with a straight shadow indicating its columnar shape. In this case, however, the dust devil is somewhat curved and kinked---its shape is best seen in the shadow it casts to the right. A thin, light-toned track has been left by the dust devil as it moved eastward across the landscape. Usually, such tracks are darker than the surroundings, in this case the light tone might indicate that the dust being removed by the passing dust devil is darker than the surface underneath the thin veneer of dust.

Dust devils most typically form when the ground heats up during the day, warming the air immediately above the surface. As the warmed air nearest the surface begins to rise, it spins. The spinning column begins to move across the surface and picks up loose dust (if any is present). The dust makes the vortex visible and gives it the "dust devil" or tornado-like appearance. This dust devil occurred at an optimal time for dust devils whether on Earth or Mars---around 2 p.m. local time in the middle of Northern Hemisphere Summer. North is up, sunlight illuminates the scene from the left (west), and 500 meters is about 547 yards. The shadow cast by the dust devil goes off the edge of the image, but the length shown here (about 1.5 km) indicates that the dust devil was a bit more than 1 km (0.62 mi) in height.

[xsrdx]

You can see some clumping along the edges of the tire tread marks

NASA geologist have so far been stumped by this characteritic of martian soil - same thing showed up in pictures of the impact area, where the outer "balloons" landed; the soil displayed some strange attributes when compressed.

[xsrdx]

You can see some clumping along the edges of the tire tread marks

NASA geologists have so far been stumped by this characteritic of martian soil - same thing showed up in pictures of the impact area, where the outer "balloons" landed; the soil displayed some strange attributes when compressed.

[Dead Corpse]

It obviously can't be water, but any type of fluid would make the dry, desert theory of Mars defunct.

[Lokibob]

 

Check out this graph from pathfinder.  Apparently, it was hit by at least 3 dust devils.  so, if this experience is any indication, Rover could be seeing the same thing.

 

An atmospheric pressure of 7 MBs is what is encountered on earth at over 100,000 (or close to it).

 

 

 

 

[cogitator]

Either that is some EXTREMELY fine sand, or that stuff is WET. You can see some clumping along the edges of the tire tread marks.

It's very cohesive, but so was the Moon dust. Remember what the footprints looked like? Still, this stuff does have a different composition, but right at the surface it can't be particularly wet, the vapor pressure in the Martian atmosphere is too low. There might be a bit of water below the surface, which is something that they want to find out.

[Paradox]

I recall reading something like that too (the 1/6th thing), but if I recall correctly from my engineering education, the force on an object (wind drag or whatever) is directly related to the density of the air. If thats the case, wouldn't it be 1/100?

[Paradox]

Ah, I forgot the velocity-squared component. After going through the boring math, I believe the answer is not 1/100, but 1/10. So a 300 mph wind on mars is about equivalent to a 30 mph wind on earth. I think...

[Lokibob]

Yes, somewhere in that neighborhood, I'd think.

I wonder if Rover has the ability to hunker down during periods of high wind.

[Paulus Invictus]

What is NASA's contingency plan for the time when the Martians drive over the hill and vaporize the Spirit?

[Dead Corpse]

There's a Remington 870 mounted right between the front cameras.

[enraged]

Hey that is one cool diorama!
Where did you find that?

[GalaxieFiveHundred]

I cannot tell a lie, found it with Google Image Search after keying in War of the Worlds. Looks like it may have been an actual miniature used for special effects on the flick. Either that, or someone's got WAY too much time on their hands.