Posted on by Nancy Atkinson

Where In The Universe #46

It’s time once again for another Where In The Universe Challenge. Test your visual knowledge of the cosmos by naming where in the Universe this image was taken and give yourself extra points if you can name the spacecraft responsible for this picture. Post your guesses in the comments section, and check back on Thursday at this same post to find the answer. To make this challenge fun for everyone, please don’t include links to the answer in your comments. Good luck!

UPDATE (3/12) The answer has now been posted below. Don’t peek before you make your guess!

Unfortunately these are not multiple Pacmen or fortune cookies, but sand dunes. These dunes, are called “barchan” which means arc-shaped, and they are on Mars. The image was taken by the Mars Global Surveyor (MGS) Mars Orbiter Camera. This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows north polar sand dunes in the summertime. During winter and early spring, north polar dunes are covered with bright frost. When the frost sublimes away, the dunes appear darker than their surroundings. To a geologist, sand has a very specific meaning. A sand grain is defined independently of its composition; it is a particle with a size between 62.5 and 2000 microns. Two thousand microns equals 2 millimeters. The dunes are dark because they are composed of sand grains made of dark minerals and/or rock fragments. Usually, dark grains indicate the presence of unoxidized iron, for example, the dark volcanic rocks of Hawaii, Iceland, and elsewhere. This dune field is located near 71.7°N, 51.3°W. Dune slip faces indicate winds that blow from the upper left toward lower right. This picture covers an area approximately 3 km (1.9 mi) across and is illuminated by sunlight from the lower left.

How did you do this week? Check back again next week for another WITU Challenge!

45 Replies to “Where In The Universe #46”

  2. Woohoo! I know this one! Barchan dunes on the Martian surface, taken by HiRISE on the Mars Reconnaissance Orbiter! Oh yes, I’ll put money on it!

    Cheers, Ian

  4. Looks like wind blown sand dunes, probably on Mars, could be any of the orbiters; guess Mars Express!

  5. What the…?

    This one got me stumped. It has a Mars/HiRISE feel to it, so that’s what I’m going to put forward as a guess, but I find all that regularity very bizarre. Almost biological.

    This week I’m really curious to know the answer.

  7. Jorge,

    I agree that it looks “almost biological.”

    Looks like footprints or ant holes or something.

    Likewise really curious to know the answer.

  8. Almost looks like birds nests under a bridge or something but since it gave away spacecraft, i’m stumped.

  10. OK, I tried to ask nice but someone put a link in to the answer again (Kevin!) From now on any comments with links to the answer will get deleted.

  12. I’m guessing these are birds nests burrowed into the side of sandstone rocks in a desert… in Mexico I think.

  13. Looks like footprints on snow. I don’t know the shape of the penguins’ feet though.
    Unless the photo wasn’t made in b&w on purpose…

  14. These are “cockroaches” on Mars. I found the picture but I’m a nice guy (no link) so after this is over, you can explain the “cockroaches”.
    Actually dunes on Mars. The only difficulty in finding the image was that there are so many similar images.

  15. I agree with the swarm of pacmen idea. Now how do you get them into the video games?

  18. This is the starfleet armada from upsilon Andromadea, set against the backdrop of our galaxy, coming to clean our clokcs out. 🙂

    If you look at the horseshoe shaped objects under magnification there is a shadowing effect. This suggests that these might be little “hoods” which lead to holes or cavities. The light appear to be coming from the bottom of the picture or shining down from the bottom or bottom left. This makes me think these are raised objects and not just impressions in the surface.

    The regularity of these appears to suggest these are not geological. I suspect they are biological. Maybe these are tiny shelled animals or bivalves sitting on sand.

    Lawrence B. Crowell

  19. I love this site.

    My thoughts are these are dunes and can only be on a few places in the solar system. I’m pretty sure this is Mars, probably taken by the Hirise camera on MGS. Looks to me like they are probably formed by dust blown around rocks forming oddly shaped dunes.

  21. Algun tipo de fotografia de vuelo de aves desde la estratosfera de la Tierra, GOES tal vez.

  26. It is definately the shven hair folicles on the arse of my pastey boss taken by his bimbo receptionist.

  32. Looks more like a damaged panel than dunes to me. Some sort of self examination of a bit of space hardware that got hit by debris? ISS examining shuttle heat shields perhaps?

  33. Wow – I put up a post earlier, but it never showed….

    I’m guessing its a Google Earth shot of a wrecked Fortune Cookie Delivery Truck! =-)

    My guess: microscopic particles taken by Spirit or Opportunity on Mars

  36. Dunes on Titan, Cassinni? But gotta change my mind – too sharp and clear. I gotta go with Martian Dunes by the Mars Orbiter.

  39. The answer is obvious. This is a close up of Neil deGrasse Tyson’s cheek.

  40. Sorry to say that you got the wind direction wrong. Though these dunes are not true barchans, their steep sides are on the concavity… and indicate that wind blows from the upper left to the bottom right, not the other way around.

  42. Apologies for coming in so late, but from first sight, there was something wrong about this report and I wanted to sit back and think about it.

    These are not sand dunes. They are small depressions into the surface. The shadows give it away. If the light comes from the upper right, then how come the shadows are on the right hand side of the surface features? and the sunlit side is on the left?

    I believe these are not dunes above the surface, but are instead small depressions in the surface. So how would they be formed?

    May I suggest that we are observing a field of warm gas emissions from an under surface source of such, probably, volcanic in nature.

    So, why are they black? If the surface is a field of frozen water ice and volcanic ash, it would have been subjected to sunlight for perhaps millions of years, but under that surface would be what we normally see, a black, volcanic ash deposit. Where venting occurs, the water ice would be evaporated and the surface of the resulting depression would be fresh and not discoloured by long term exposure to sunlight.

    There is no sign of any dust bleeding away from one “dune” to the next. The edges of each is very clear and sharp. The shadows are not in line with the direction of sunlight.

    These are depressions into the surface, not dunes.

  43. And then I go and look at the image provided by NASA and see very clearly that you have placed the image upside down, but with the same verbal details. Thus the image YOU SHOW should read, the wind comes from the upper left to the lower right and the sun should come from the lower left.

    Bah!

  44. Chris Coles, go to
    16° 42? 52.43? S, 71° 50? 2.7? W
    These are the same barchans here on earth and don’t tell us that these are “depressions in the surface”

  45. Ok, yes, you guys are right and I’ve updated the post to have the wind blowing in the right direction. Sorry, and thanks for catching the mistake.

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