Mysterious origin

European probe finds “spiders” on Mars

(Bild: ESA/TGO/CaSSIS)

One of the aims of research on Mars is to find possible evidence of life. In this context, the European Space Agency (ESA) has now made people sit up and take notice: The "Mars Express" probe had discovered "signs of spiders" near the "Inca city" in the planet's southern polar region.

The news that, under certain circumstances, tiny amounts of liquid water can form beneath the surface of the Earth-like planet during the day as a result of solar radiation was already considered a scientific sensation - and fueled speculation as to whether life could actually be possible there.

Message with a wink?
At first glance, the ESA images would seem to have the potential to fuel this even further, but the title of the discovery should actually be seen as a wink. On its website, the organization explains what the "spiders" might actually be.

The picture shows dark spots with tendrils that are eerily reminiscent of spiders. They are scattered in large numbers on the left-hand side and irregularly across the rest of the picture.

(Bild: ESA/TGO/CaSSIS)

Instead of supposed insects, the probe may have captured small dark formations that are created when the spring sunlight falls on layers of carbon dioxide that have been deposited during the dark winter months.

The sunlight causes the carbon dioxide ice on the ground to turn into gas, which then builds up and breaks through the ice sheets above. In the Martian spring, it then tears open the layers of ice, which can be up to one meter thick.

Spots up to one kilometer in diameter
The escaping gas, which is laden with dark dust, shoots up through cracks in the ice in the form of tall fountains or geysers before falling back down and settling on the surface. This creates dark patches with a diameter of between 45 meters and one kilometer. This creates the characteristic "spider-shaped" patterns under the ice.

If you take a closer look at the images, you can also see that the photographed objects are many times larger than spiders in reality. The dark spots extend over a part of Mars nicknamed "Inca City" and stretch across towering hills and vast plateaus.

"Inca city" on Mars

The Angustus Labyrinthus is a complex of intersecting valleys or ridges near the south pole of Mars. The reason for the nickname: The linear, almost geometric network of elevations is reminiscent of the ruins of the Incas. It is not yet entirely clear how Angustus Labyrunthus was formed.

It could be that sand dunes have turned to stone over the course of time. Or perhaps material such as magma or sand seeped through fissured layers of Martian rock. The "Inca city" was discovered in 1972 by NASA's "Mariner 9 probe".

"Mars Express" on an important mission
The new images were taken with the high-resolution stereo camera of "Mars Express". The probe has already revealed a great deal about Mars over the past two decades, mapping minerals, investigating the composition and circulation of the atmosphere, probing beneath the crust and studying the Martian environment.

For example, he provided the most comprehensive map of the chemical composition of the atmosphere, investigated the innermost Martian moon Phobos and traced the history of water on the planet. This has shown that Mars once had environmental conditions that may have been suitable for life.