HiRISE images

Ripples in a crater
Published 5/20/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: Many small craters on Mars are filled, at least in part, by small dunes or ripples. It's one of the distinguishing features of Mars -- a surface marked by geology both old (craters) and young (dunes). This particular crater isn't so old -- boulders surrounding it were made from rocks flung from the impact when it formed, and they are usually one of the first things to erode away as a crater ages. (HiRISE ESP_026726_1790) read more ❯

Dust and oddities
Published 5/17/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: In the dustier regions of Mars, there are many small dark streaks on steep slopes that we don't understand well. Because we don't know much about them we call them "slope streaks", which is not the most imaginative name. They are actively forming on Mars today, though, and seem to be triggered by a disturbance like a nearby earth(mars)quake or a strong wind. Over the next several decades they slowly fade away. (HiRISE ESP_014394_2045) read more ❯

Wind and hills
Published 5/16/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: Blueish and yellowish ripples wind their way around a bright hill. The yellowish ones are probably not moving anymore, but the blueish ones are likely still active from time to time. (HiRISE ESP_020889_1320) read more ❯

Swirls like ribbon ice cream
Published 5/14/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: When the wind erodes layered rocks, it can create a dramatic swirly pattern like this. It looks like ribbon ice cream to me. Mmm, rocks. (HiRISE ESP_011582_1730) read more ❯

One perfect barchan on Mars
Published 5/13/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: In nature most dunes pile on one another or strongly influence each other. But occasionally, like a perfect flower or crystal, you find a perfectly shaped dune. Here is a crescentic dune, called a "barchan", formed by winds moving from right to left. (HiRISE PSP_007676_1385, NASA/JPL/Univ. of Arizona) read more ❯

So beautiful
Published 5/10/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: The dunes can be so beautiful on Mars. What a lovely vacation spot this would be, provided you brought a large supply of oxygen, food, and a heat source to keep you warm. (HiRISE ESP_026416_1620) read more ❯

Sand, wind, and dust
Published 5/9/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: This is what dunes look like in the deepest part of Mars, where the air is full of bright dust that constantly settles out onto everything. The wind helps to clear off the sand dunes (blue in this image) in two ways: one is by dust devils that leave crooked tracks like drunk vacuum cleaners, and the other is by sand avalanches down steep dune slip faces (HiRISE ESP_025278_1345). read more ❯

Tweed
Published 5/8/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: Patterns within patterns (metapatterns?).  These small martian dunes shown an unusual complexity in their crossing lines, indicating that they were formed by winds from several directions (and it is likely that those winds changed over time). What do you think, should it be the next thing in tweed fashion after houndstooth and herringbone? read more ❯

High summer near the north pole of Mars
Published 5/6/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: It's high summer in the northern hemisphere of Mars. Here, dark dunes near the north pole have finally lost the seasonal ice that blankets them and turns them white for most of the year. For a brief time we can see the true contrast between the dark dunes and the bright terrain they are slowly crawling over. (HiRISE ESP_026598_2650) read more ❯

Colors and waves
Published 5/3/2012 in Lori Fenton's Blog Author lfenton
A piece of Mars: Here are some lovely ripples on Mars. In the same field of ripples, there are large wavy white ones and small complex blue ones. Why are there two different types, made distinct by their color, size, and shape? Nobody knows, but it's a good bet the sand grains that they're made of have different sizes and composition. Regardless of why they look the way they do, they're still quite pretty. (HiRISE ESP_026388_2300) read more ❯