There may be no insects on Mars, but new photographs taken from an orbiting spacecraft have revealed a large number of “spiders” that seem to sneak across the dusty surface.
Of course, they are not real, live arachnids; rather, they are dark, thin marks on the Martian surface created entirely by non-biological processes. They are called “spiders” because that’s what they look like, with a central dark spot surrounded by thin stripes radiating outward.
They form as a consequence of seasonal changes on the red planet through cold extremes followed by spring warming, reports ScienceAlert.
‘Spiders’ photographed on the surface of Mars by the Trace Gas Orbiter (ESA/TGO/CaSSIS).
Although Mars experiences seasons thanks to an axial tilt similar to that of Earth, those seasons are very different from those we experience on our home planet. Winter temperatures drop below -123 degrees Celsius and almost everything freezes.
In winter almost all of Mars is frozen
That includes carbon dioxide, which forms surface deposits of a substance known as dry ice here in the earth. As the cold winter begins to give way to spring, temperatures are warm; But while normal ice would melt in the warming atmosphere, dry ice does not. Instead, it sublimes directly into gas.
When this happens to the ice at the bottom of the tank, the pressure increases until a mini explosion and the surface of Mars explodes like a boil. Cracks appear in the ice, and darker, dusty material from below the surface is carried and sprayed with escaping gas in huge geysers, creating dark spots that can measure up to a kilometer wide, indicates ScienceAlert.
The radial lines are actually below the surface of the ice. In images from the High Resolution Stereo Camera (HRSC) of the European Space Agency’s (ESA) Mars Express Orbiter, dark spots, like freckles, can be seen scattered across the sand.
Inca City of Mars, photographed by Mars Express. If you look closely, you can see the dark specks where the ‘spiders’ lurk (ESA/DLR/FU Berlin).
However, the Color and Stereo Surface Imaging System (CaSSIS) instrument on board ESA’s ExoMars Trace Gas Orbiter can see in a wider wavelength range and reveals the spider tendrils radiating outwards. , just below the surface of the ice.
A new image of the Inca city of Marsa strange formation named so because it looks like ancient ruins seen from above, reveals freckled spots all over it, showing how active the surface of Mars can become when it begins to wake up with warming spring days, says ScienceAlert.
It’s fascinating to think what it would be like, with the ice cracking open and dust whistling through the air. Maybe, if we’re lucky, one day Martian explorers will be able to send home images of the strange alien process in action.
