Gigantic Tornado Spotted on Mars

[pokerfan]

The Mars Reconnaissance Orbiter has now spotted a gigantic Martian dust devil roughly 20 kilometers (12 miles) high, churning through the Amazonis Planitia region of northern Mars. The HiRISE camera (High Resolution Imaging Science Experiment) captured the event on March 14, 2012. Scientists say that despite its height, the plume is just 70 meters (70 yards) wide.

Yikes! After seeing trucks thrown about by the tornadoes in Dallas yesterday, it makes you wonder how the MER rovers and even the Curiosity rover would fare in an encounter with a 20-km high twister.

http://www.universetoday.com/94437/new-gigantic-tornado-spotted-on-mars/

[Dead_Parrot]

1. Interesting question...

Given how rarefied the atmosphere is, my gut feeling is that this would be a pretty ephemeral affair - probably no worse than a gust of wind on earth. Would be fun to see some numbers, though...

[jberryhill]

2. Why would God be punishing Mars?

[pokerfan]

3. Martians legalized gay marriage?

[Confusious]

4. 'cause mars is red!

Damn commies!

[jberryhill]

12. At least we can bomb the moon already!

[mike_c]

5. bear in mind the low atmospheric density....

Mean surface atmospheric pressure on Mars is about 0.087 psi, compared with 14.7 psi on Earth. So high velocity winds on Mars pack correspondingly less punch than similar winds on Earth.

[pokerfan]

6. True

but also consider the lower surface gravity (about a third of Earth's) would mean that it would take less wind to lift material. I suspect the author was probably being tongue in cheek when speculating about rovers being tossed about. Still, given enough velocity...

[Confusious]

7. Rovers are only about 60lbs on mars

Enough velocity and wind could move them around.

It doesn't have to lift them, just knock them over, and they're done.

[pokerfan]

8. Dust devil caught by the Spirit rover

[mike_c]

9. yeah, but it's still thin, thin atmosphere....

That 60 lb object still has as much mass on Mars as it has on Earth. It's like trying to knock over a cinder block with a feather. Sure, you can hit it hard, all day long, but it's just not possible to accelerate the air fast enough to convey enough force to knock it over with so little density to push with. Those dust devils are lifting DUST, not stones and certainly not boulders.

[Confusious]

10. Mass matters, but in this case

It's all about weight. A feather could push a brick in zero G if it was going fast enough, as an example.

Its also about F=MA. Little mass, lots of acceleration, lots of force. The other side, the rover, F=MA, which is Weight=(Mass)(Gravity)

If the Force > Weight, over she goes.

[jberryhill]

11. Turn The Machine On!

[scubadude]

13. Actually the mars rovers have benefitted from these dust devils.

It was thought early on that the rovers would quit because dust would interfere with their solar cells. The dust devils have actually scoured the solar cells clean, thereby allowing them to perform way beyond their expected lifetime. These dust devils are not powerful enough to lift a mars rover.

Scuba