The image is Mars Cloud Map Captured High resolution stereo camera (HRSC) Equipment On ESA's Mars probe “Mars Express”.
Leech waves on Mars are created when wind encounters an obstacle and builds up on the “leeward” or leeward side. Image courtesy of ESA / DLR / FU Berlin.
Mars Express's elliptical orbit allows the HRSC camera to observe the surface from a low altitude to map the planet at the highest possible resolution, but also to capture observations at a lower resolution from a higher altitude, covering a much larger portion of the surface in a typical edge-to-edge field of view.
These high altitude observations are ideal for observing Martian atmospheric phenomena.
More than 20 years have passed since the launch of the Mars Express mission, and a vast amount of image data on Martian atmospheric phenomena has been accumulated, which has great potential for scientific applications.
“Martian clouds are as diverse and fascinating as those seen in Earth's skies, but they also have some features that are unique to the Red Planet,” said Dr Daniela Tyrsch, researcher at the German Aerospace Center (DLR).
“One of my favorite phenomena is the beautiful 'cloud street' – a linear line of fleecy clouds that form around the rise of the giant volcano Tharsis Mons and the lowlands of the Northern Hemisphere during the Northern Hemisphere spring and summer.”
“They are similar to cumulus clouds on Earth, but form under different atmospheric conditions.”
“Impressive dust clouds stretching hundreds of kilometres have also been observed, a phenomenon that is fortunately not experienced on Earth.”
Dust plays a major role in the Martian atmosphere and climate.
Rare upwelling events can cause beige, dusty clumps to drift through the planet's atmosphere.
Large differences in temperature and air pressure during certain seasons can create stronger than normal winds and kick up large amounts of dust from the Martian surface.
The dust cloud rising from the summit of the giant volcano resembles an eruptive cloud, even though it is no longer active.
Large, swirling dust storms and cyclones are also observed near the Martian north pole every year.
Studying these phenomena is crucial for scientists to understand the Martian atmosphere and air mass circulation.
Rolling “gravity clouds” are one of the most common formations on both Mars and Earth.
They are found in the mid-latitudes of both hemispheres in winter, as well as over the Tharsis volcanic plateau in the Southern Hemisphere winter.
Lee waves are a special type of gravity cloud that can accumulate on the lee side of ridges, mountains, and other obstacles, forming repeating ridges.
Some of the cloud types studied are specific to certain locations and seasons, but there are also clouds such as “crepuscular clouds” that appear in the early morning at any time and any place throughout the year.
The new atlas provides valuable insight into the physics of clouds and storms, their appearance, and when and where they form.
This knowledge will not only help us better understand the dynamics of Mars' atmosphere and climate cycles, but will also be useful in studying the climates of other planets, such as Earth and Venus.
“ESA has extended the Mars Express mission until at least 2026, which will allow us to continue to enrich the database and further our understanding of the Martian atmosphere,” Dr Tilsch said.
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Daniella Tirsch others2024. Clouds and storms captured by HRSC – a catalog of Martian atmospheric phenomena. EPSC Abstract 17, EPSC2024-44; doi: 10.5194/epsc2024-44
Source: www.sci.news
