NewScientist.com news service
Posted on 08/26/2004 7:29:38 PM PDT by ckilmer
Martian teardrop carved in crater
18:04 24 August 04
NewScientist.com news service
Wind sculpted basaltic sand dunes millions of years ago (Image: ESA/DLR/FU Berlin G. Neukum)
Dark, rippling dunes of volcanic ash - similar to Hawaii's black sand beaches - cast a teardrop shape in an ancient Martian crater, reveal the latest images from Mars Express.
Wind is likely to have carved the 12-kilometre-long tear shape a million or more years ago when the Martian atmosphere was thicker, says Gerhard Neukum, principal investigator of the High Resolution Stereo Camera on Europe's Mars orbiter.
Now, the atmosphere has thinned so much that the dune's shape is likely to remain fixed for at least hundreds of thousands of years, he says.
Perspective views such as teardrop take hours to process by hand (Image: ESA/DLR/FU Berlin G. Neukum)
The sand's dark colour suggests it is basaltic, or volcanic in origin. Neukum believes an impact created the 45-kilometre-wide crater perhaps a billion years ago, ejecting the basalt from a subsurface layer of volcanic ash.
The fact that the sand remains dark - as opposed to reddening with time - suggests the material has not been altered by water or other chemical processes.
Elliptical path
"This blackish, bluish material was not so much known before," Neukum told New Scientist. Unlike Mars Express, previous orbiters have not been able to image the planet in full colour and 3-D. "Previously, one could not distinguish it very well - it appeared darker but it could have been any colour."
The camera, which has been taking data since January 2004, captured the latest images in May at a resolution of 16 metres. The two-kilometre deep depression lies in a basin of craters in Mars's southern hemisphere called Argyre Planitia.
"The HRSC is doing very, very well," says Neukum. But he adds that right now the camera is taking images for just 10 minutes during each of Mars Express's seven-hour orbits. That is because the closest part of the spacecraft's orbit, which takes an elliptical path around the planet's poles, changes with time.
Now the closest approach is relatively far from the planet and occurs over the planet's night side, limiting photo opportunities. But the geometry will begin to improve again in September.
Maggie McKee
On second thought, don't.
who is Richard Hoagland
Some freak who's made a living selling the "Face on Mars" nonsense.
I don't think anything like that is being claimed here.
the resolution is too good for any confusion
Cool formation.
Looks pretty cool.
As for Richard C. Hoagland...well, he probably already knows about this one, and is currently ready with another one of his absurb theories.
He's probably going to claim that some ailen carved this out to show their sadness of Mars losing it's atmosphere. :-P
< / chortle> .....And he'll use "sacred geometry" to "prove" it.
That's some teardrop...12 km long. I'd hate to see the eye it came from
LOL! You beat me to it while I was typing.
(I'm too darned slow!)
A few got away in special rockets and made it here to become Democrats.
We need to hire some help for all those folks in Washington who tell us how to spend our tax dollars.
I think was done by the european space agency.(their money)
I'm starting to grieve now.
don't see no 19
You an expert on that?
:-P
I guess I did beat you. However, you put more detail in Richard C. Hoagland's response. In terms of which is the better response, you get the points.
That being said, IMO, the only thing Richard C. Hoagland cares about in politics is, whomever gets us to Mars to prove (disprove. *Snicker*) his crazy theories. True, he probably believes some of the crazy conspiracies surrounding Bush. But, since Bush announced the Moon/Mars plan, he's actually semi-happy about that (though he probably wants it to be immediate. :-/).
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