The high-quality stereo camera aboard the Mars Express received this remarkable shot of dust clouds (right) near the north polar cap of the Red Planet in April 2018. It was one of several small dust storms observed in recent months on Mars. At the end of May, a much larger storm was formed in the south-west, which in a few weeks grew into a global dust storm around the planet.
The intensity of the event suggests that little sunlight comes to the Martian surface. This is an extreme situation, because the 15-year-old NASA Opportunity Rover did not manage to charge its batteries and remains in hibernation mode from mid-June. Dusty Martian storms form constantly in the southern summer season, when the planet is located closer to the Sun in an elliptical orbit. The increased stellar luminosity leads to an increase in temperature contrasts, due to which air currents more easily raise dust particles from the surface.
Martian dust storms are impressive, both visually and in terms of intensity and duration. The current storm is monitored from the five orbits of ESA and NASA, and the Curiosity rover surveys from the surface through the operation of a nuclear battery. Understanding the process of forming and developing large-scale storms can significantly affect future Martian missions.