Introduction

Shown in this HRSC color image captured in April 2018 is a precursor of this year’s unusual intense dust storm season on Mars. This small-scale, local storm front is situated north of Utopia Planitia, in the vicinity of the north polar ice cap of Mars. Another, much larger storm emerged further southwest in Arabia Terra at the end of May, and developed into a global, planet-encircling dust storm event within several weeks. The latter is one of the most intense dust storms ever observed on Mars and is currently monitored by all five active ESA and NASA orbiters.