ESA’s ExoMars Trace Gas Orbiter has taken an image that surprised scientists. At first view, it looks like a giant tree stump, but in original, it is an ice-rich impact crater on Mars.
The image was taken on 13 June 2021 in the vast northern plains of Acidalia Planitia, centered at 51.9°N/326.7°E. The crater in the image is in an area of Mars known as Acidalia Planitia.
The image shows the pattern of large concentric rings on the surface that looks like a tree stump’s rings.
Just like tree rings offer information on Earth’s past climate, the pattern in the crater reveals details of the Red Planet’s history, too.
The crater’s interior is filled with deposits that are probably water-ice rich. It is thought that these deposits were laid down during an earlier time in Mars’ history when the inclination of the planet’s spin axis allowed water-ice deposits to form at lower latitudes than it does today.
The crater deposits have some peculiar features: Quasi-circular and polygonal fractures are some of these physical features. According to experts, these features are likely a result of seasonal temperature changes.
Changes in temperature causes cycles of expansion and contraction of the ice-rich material, eventually leading to fractures.