Recently, dirty-yellow crystals were spotted in one of the images taken by the Curiosity rover. They are sulfur, a substance that has already been detected many times in the rocks that make up the Martian soil. However, this is the first time it has been found in pure form.

Sulfur crystals in the image
NASA recently published a close-up image of a fragment of Martian soil. It was taken by the Curiosity rover on May 30, 2024. At that time, the rover drove over a piece of rock, crushed it, and the team operating the rover tried to point the camera at it.
The image published by phys.org shows dirty-yellow crystals. This is sulfur. Such formations are common on Earth, so now we know that they also exist on Mars.
In general, there is nothing surprising about finding sulfur crystals on the Red Planet. One of the most common types of minerals on this dry planet is sulfates — salts of sulfuric acid. However, until now, they had only been found as part of compounds. Now scientists have detected crystalline sulfur in its pure form on Mars for the first time.
Traces of magmatic activity
Still, there is one interesting aspect to the discovery of sulfur crystals. For them to form, volcanic activity is required. Mars, however, has long been considered a geologically dead planet. This makes it very interesting to determine when these crystals actually formed.
It is quite possible that this happened only a few hundred million years ago. This would mean that Mars remained sufficiently active until relatively recently. And therefore, theoretically, it may be possible in the future to return it to such a state.