What's up with the strange colors of these dunes? Mars isn't really blue and gold, it's just that this picture was taken in infrared wavelengths to better show the composition of the sand here. But these dunes, known as "barchans," would look striking in any light: they often form cool horns or notches on their steep leeward sides.
Mars is a crazy place. In recent years we’ve discovered some of the strangest things on the Red Planet: ice spiders, Swiss cheese terrain, and perfectly spiral-shaped lava tubes.
And the more we explore our near planetary neighbor, the weirder the things we find get. NASA’s Mars Reconnaissance Orbiter, which has been circling Mars since 2006, provides the clearest and highest-resolution images of the planet’s surface. Looking through the image archive of its HiRISE camera, which can resolve things about a meter wide on the ground, reveals a vast supply of strange and wonderful things.
Here we share some of the orbiter’s most recent weird sightings from the last few months. The images provide incredible scientific insights into Mars. But, perhaps just as important, they are beautiful, fascinating, and reflective of the alien world that sits not too far from our own.
Just a note on the colors in these images: HiRISE has cameras that see in slightly different wavelengths than our own eyes. Many of the photos it produces are in “false color,” meaning the different wavelengths have been assigned colors for purposes of clarity or to highlight an important feature. There are no actual turquoise dunes on Mars. But the false color pictures do allow scientists to differentiate various textures and materials on Mars.
At first glance, you might mistake this for a close-up of human skin. It’s actually a bunch of polygonal shapes that would normally indicate some sort of subsurface water processes. Instead, scientists realize that they are simply intersecting sand dunes.
What’s up with the strange colors of these dunes? Mars isn’t really blue and gold, it’s just that this picture was taken in infrared wavelengths to better show the composition of the sand here. But these dunes, known as “barchans,” would look striking in any light: they often form cool horns or notches on their steep leeward sides.
The ceaseless winds of Mars create sand dunes all across its surface. But beneath these dunes in Syria Planum are bright deposits with steep faces and sharp, weathered ridges. These lower deposits are evidence that in Mars’ past the winds were much more ferocious.
One of the best images from Mars ever taken was a 2009 pic showing the tracks of dust devils on the sand. HiRISE here provides an updated shot of the same area, showing completely different tracks, indicating that at least one dust storm has wiped the slate clean in the meantime and new dust devils have run over the ground.
Water is thought to exist in large deposits beneath the Martian surface. When it disappears, the ground sinks and creates scallop-shaped depressions and polygonal troughs. The formations are known as “thermokarsts,” a variety of which can be seen here.
Mars is so cold that frozen carbon dioxide, or dry ice, remains from season to season at is south pole. The white areas of this image are this residual dry ice cap while the darker parts are water ice with dust and particles trapped in it. As to why that formation on the lower right looks like North America, who knows?
The curvy lines seen here form what is called “brain terrain.” It forms atop ice at the base of a small hill, though scientists still don’t know exactly why it creates this cantaloupe-like texture.
These odd and tortured raised ridges both look strange and leave scientists without any good explanation as to how they formed. Some say they might have been left behind by an ancient ocean or perhaps ancient glaciers. For now, the formations remain a mystery.
Though they look like tree rings, these formations are actually layers of bedrock in a small crater inside of Schiaparelli Crater. In some places, a dark sand covers the layers, sitting atop ridges that no one is quite sure how to explain.
