Martian Dune Mystery Solved by Bouncing Sand Grains

I remember the martian sand dune formations which many claimed to be buried concave structures. The sand formations were indeed interesting but there was also the mystery of "why do the formations make up and follow a certain pattern as if they were created by intelligent -artistic- beings?"..

What I am referring to are these:





I found this article very interesting and thought I should share it with everyone here.


WIRED: Martian Dune Mystery Solved

The finding could help solve other puzzles in the Martian landscape. Earlier models predicted that crescent-shaped sand dunes called barchan dunes should grow to at least 500 meters long — but many are only 100 meters.

And the Mars rover Opportunity has found sand ripples made up of particles only 100 micrometers in diameter, so small that scientists had expected them to stay aloft once kicked up.

The new model could explain both riddles by showing that splashing can keep particles moving at low wind speeds. Slow-moving sand grains don’t travel far and therefore make short dunes, but even tiny particles can get pushed into ripples, Kok says.

One mystery solved, a million others to go..

[edit on 11-2-2010 by AlKashif]

[edit on 11-2-2010 by AlKashif]

reply to post by AlKashif


Really interesting theory. I'm not sure if it's correct or not but it is compelling nonetheless.

S&F

IRM

reply to post by AlKashif
That's an interesting article.

The way sand grains knock each other around turns out to make all the difference, Kok says. Because Martian gravity and air density are so much lower than Earth’s, a small kick from the wind sends sand particles on Mars flying much higher, up to a meter off the ground. “It’s like playing golf on the moon,” Kok says. Particles get caught in stronger winds as they rise, causing them to pick up speed and ultimately slam into the ground, where they kick up more particles and start the cycle over. “This splashing process is really efficient,” Kok says. “It can keep saltation, or sand blowing, going on Mars at relatively low wind speeds.” These jumping sand grains can create ripples over time even without high sustained winds, he says.

OP Article

It reminds me of a thread from last year about water loss on Mars. No magnetosphere means the solar wind is slowly removing the atmosphere from Mars. The water loss is attributed to this process...in theory. I can't find the article right now, it had figures for estimated loss of Martian material to space...sand, dust etc. It amounted to many tons a year. This comes close...

Nov. 21, 2008: Researchers have found new evidence that the atmosphere of Mars is being stripped away by solar wind. It's not a gently continuous erosion, but rather a ripping process in which chunks of Martian air detach themselves from the planet and tumble into deep space. This surprising mechanism could help solve a longstanding mystery about the Red Planet. "It helps explain why Mars has so little air," says David Brain of UC Berkeley, who presented the findings at the 2008 Huntsville Plasma Workshop on October 27th.

Solar Wind Rips Up Martian Atmosphere