Scientists create a cloud atlas to study Mars’ atmosphere

An example of cloud streets over Vastitas Borealis, a large area near the North Pole mostly devoid of craters. Credit: ESA/DLR/FU Berlin/A. Cowart.

Mars may have a thin atmosphere, but its skies are filled with fascinating cloud formations and dust storms.

Now, thanks to a new tool called the “Mars Cloud Atlas,” both scientists and the public can explore these weather phenomena in more detail.

The Cloud Atlas is a searchable database containing 20 years of images from the European Space Agency’s (ESA) Mars Express mission. This collection is helping researchers learn more about the Martian atmosphere and its climate.

The Mars Cloud Atlas was developed by the German Aerospace Centre (DLR) and presented at the Europlanet Science Congress (EPSC) 2024 in Berlin by Dr. Daniela Tirsch of DLR.

The images in the atlas were taken by the High Resolution Stereo Camera (HRSC) on board the Mars Express spacecraft, which has been orbiting Mars since 2005.

Mars’ unique clouds and dust storms

Even though Mars has a much thinner atmosphere than Earth, it still experiences a wide variety of cloud types.

These clouds are made from water and carbon dioxide ice crystals, as well as dust particles. Some clouds on Mars are similar to those on Earth, while others are unique to the red planet.

One of Dr. Tirsch’s favorite Martian cloud formations is known as “cloud streets.” These are long rows of fluffy clouds that form around Mars’ massive volcanoes, such as the Tharsis region, during the northern spring and summer.

While these clouds look like cumulus clouds on Earth, they form in completely different atmospheric conditions on Mars.

Dust storms are another major feature of Mars’ weather. Huge dust clouds can stretch across hundreds of kilometers. These storms are driven by strong winds that lift large amounts of dust from the Martian surface.

In some cases, these dust clouds look like volcanic eruptions, even though Mars’ volcanoes are no longer active.

The images in the Mars Cloud Atlas will help scientists understand the role dust plays in Mars’ atmosphere and how it affects the planet’s climate.

For example, each year, scientists observe large spiral dust storms near Mars’ north pole. Studying these storms helps researchers learn more about how air moves across the planet.

One common type of cloud seen on both Earth and Mars is called “gravity clouds.” These clouds form in waves when wind flows over mountains or ridges. Another type of cloud, known as “twilight clouds,” can appear in the early morning at any time of the year.

The Mars Cloud Atlas is still growing, and with the Mars Express mission extended until at least 2026, scientists will continue adding new images to the database. The goal is to create a complete picture of Mars’ atmosphere and its changing climate.

This research will also help scientists study the climates of other planets, like Earth and Venus.

The Mars Cloud Atlas is a valuable tool for both scientists and space enthusiasts, offering a new way to explore the dynamic and ever-changing skies of the red planet.