Scientists explain the appearance of a "doorway" in the Martian rock in the photo of the Curiosity rover

Last week, the US National Aeronautics and Space Administration (NASA) published a curious snapshot from the Curiosity rover, which continues to surf the expanses of Mars. The photo showed a rock with a "doorway" - a hole with very smooth edges.

The photo was later painted to match the colors of the landscape of Mars (on the cover of the article). The panorama of the object, obtained by merging multiple images, can be viewed in full resolution on the website Gigapan.

The image of this hole in the rock made a lot of noise on the Web. So, Reddit users started building theories about the entrance to the caves of the Martians and guess about the growth of the inhabitants of the Red Planet, which should be very small. According to preliminary estimates, the height of the opening is definitely less than 1 meter (according to other sources, it is 35-40 cm at all).

In fact, this gap formed naturally. About it writes portal Live Science, which received comments from several experts.

So, the British geologist Neil Hodgson, who studied the geology of Mars, believes that the "door" was formed as a result of erosion. Near the opening, rocky layers and layers are clearly visible. These are silt deposits with harder sandy rocks. Perhaps they formed several billion years ago in sedimentary conditions in a river or in a windswept dune.

The image also shows several natural vertical cracks, some caused by the weather conditions on Mars. And a small cave or "door" appears to have formed where the vertical cracks intersected with the layers.

Probably, a boulder broke off the rock and simply fell out under its own weight, forming a hole in the shape of a doorway. Gravity on Mars is not as strong, but it is still enough for this, Hodgson added.

The culprit of such a formation may be a stone lying on the surface in front of this “opening”. It has a fairly even vertical edge, possibly because it fell relatively recently and has not been exposed to the Martian winds. All this is quite natural and is similar to the rock outcrops that can be seen in many arid places on Earth.

Geologist Nicholas Mangold of the University of Nantes in France agrees with this version. He noted that the appearance of cracks in two directions, creating an "open box" with the appearance of a door, is a completely natural process.

The cracks may have formed before the rock was exposed, due to the hydraulic pressure of the water, or as a result of thermal stress caused by seasonal temperature fluctuations on the planet's surface.

Mangold believes that even marsquakes are not needed to form such dips. And Angelo Pio Rossi from the Jacobs University in Bremen agrees with this. He added that any stone block insulated by cracks could end up falling down a slope, even if the slope is gentle.

However, all these explanations did not satisfy the netizens. Some of them are looking forward to when Curiosity can get close to the "door" to look inside.