This observation was taken on December 3, 2021, from an altitude of about 28,000 km. It was mid-summer in the northern hemisphere. This early-morning EXI observation reveals a large “spiral storm” covering much of the Martian North Polar Cap and the surrounding arctic plains. The storm involves both dust clouds (the tannish “core” of the storm) and water-ice and/or carbon-dioxide clouds (bright white). Along the morning limb (right of center), pervasive water-ice clouds and ground fogs are rotating from night into sunrise, where they will soon dissipate as sunlight warms the atmosphere.

The EXI camera system onboard the Emirates Mars Mission (EMM) collects images at three visible and two ultraviolet wavelengths – providing a “weather satellite view” of Mars. The color composite presented here is assembled from images taken through EXI’s blue, green, and red filters (centered at 437, 546, and 635 nanometers); north is to the top. The contrast has been adjusted to enhance the visibility of surface and atmospheric features.

The Hope probe has been capturing new observations of Mars’ atmospheric dynamics using its three instruments to open up new horizons in the Red Planet’s exploration.

Here, we see images of Mars captured by EXI showing the diurnal cycles of water ice clouds engulfing the planet, the first such observations around Mars. A band of clouds observed by EMIRS near the equator of Mars and near Martian volcanoes is also seen, while a complementary set of observations made by EMUS, illustrate thin clouds of atomic hydrogen surrounding the Red Planet, showing the powerful potential for new insights opened up by combining EMM's unique diurnal and seasonal observations.

Coordinated observations made by the EXI camera and the EMIRS instrument provide details of the surface and lower atmosphere of Mars over time scales of minutes to days.

Starting in late December 2021, EXI and EMIRS monitored a rapidly evolving regional dust storm as it expanded to a size of over several thousand km. A series of EXI and EMIRS “globes” are presented here (orientated with north to the top), documenting the growth and dissipation of the storm over nearly two weeks.

On 5 January 2022, the EXI camera system onboard the EMM mission obtained this half-illuminated view of Mars — the sun was just setting near the center of the disk. When the images were taken, the Hope spacecraft was at an altitude of about 40,500 kilometers above the surface. This view is centered at 12.3°S latitude, 94.8°E longitude, with North toward the top of the image. The season was mid-winter in the southern hemisphere (Ls = 153°). This color composite was assembled from images taken through EXI’s blue, green, and red filters (centered at 437, 546, and 635 nanometers). These images are “quick look” products which retain some artifacts of the camera system, and the contrast has been adjusted to enhance the visibility of surface and atmospheric features. A number of regional dust storms have been observed in this region of Mars over the past several weeks. The prominent dark “shark’s fin”, to the left of center, is a volcanic feature known as Syrtis Major. A massive dust storm (about 2500 km across) is approaching from the east (green arrows) and is partially obscuring Syrtis. To the south, the Hellas impact basin (the largest crater on Mars – about 2300 km across) is completely shrouded by dust clouds (blue arrows).
Two of NASA’s lander missions are being affected by these storms. Jezero crater (marked by the yellow “+”), home to the Perseverance rover, is within about 150 km of the dust storm. Perseverance is powered by a plutonium “battery”, so operations are not directly impacted. However, the solar-powered Ingenuity helicopter (Perseverance’s companion) has temporarily suspended flights until the atmosphere clears. The Mars InSight lander is located about 3500 km south-east of Perseverance. On 7 January 2022, dust lofted into the Martian atmosphere by these storms significantly reduced the sunlight reaching the solar-powered InSight – forcing the spacecraft to enter a protective safe mode and to suspend all but essential functions. The skies had cleared sufficiently by 19 January 2022 for InSight to resume normal operations. As Mars approaches southern spring, dust storm activity typically becomes more likely, leading to increasing amounts of dust suspended in the atmosphere. The EMM mission will be a valuable orbiting asset to document the location and evolution of dust storms occurring across the planet!

On 15 September 2021, the EXI camera system onboard the EMM mission obtained a set of multispectral images of this fully illuminated hemisphere of Mars. At the time the images were taken, the Hope spacecraft was orbiting at an altitude of about 19,900 kilometers above the surface. This view is centered at 4.0°N latitude, 66.8°E longitude, with North toward the top of the image. The season was early winter in the southern hemisphere. The color composite presented here was assembled from images taken through EXI’s blue, green, and red filters (centered at 437, 546, and 635 nanometers). These images have been “calibrated” to remove several types of artifacts introduced by the camera system, and the contrast has been adjusted to enhance the visibility of surface and atmospheric features. The prominent dark “shark’s fin” at the center of this view is known as Syrtis Major. In 1659, the renowned Dutch astronomer Christiaan Huygens included this dark marking in a sketch of his view of Mars through his early telescope – making this the first feature to be documented on the surface of another planet. Huygens also used repeated observations of Syrtis Major to estimate the length of the Martian day (about 24 hours). Over the following centuries, astronomers noted dramatic changes in the size, shape, and “darkness” of this feature, and it was believed by some to be related to seasonal changes in vegetation growing in and near a shallow sea. Beginning in the early 1970’s, spacecraft observations revealed Syrtis Major to result from dark sand deposits covering the gentle slopes of a massive volcanic plain. The noted variability over the Martian year is caused by winds moving fine, bright dust and coarser, dark volcanic sand across the region.
The bright feature to the south of Syrtis Major is known as Hellas Planitia. Caused by the collision of a large asteroid with Mars about 4 billion years ago, and measuring about 2,300 km across and up to 7 km deep, Hellas is among the largest impact basins in the Solar System. The interior of Hellas is often obscured by water-ice clouds. In southern winter, deposits of water ice and frost can also mantle the basin’s surface. In this view, a dust storm (the tan clouds) is swirling over northwestern Hellas.

This image was obtained on 16 March 2021 by the EXI camera system onboard the EMM mission. At the time, the Hope spacecraft was orbiting approximately 1366 km above the surface of Mars. The image scale at center is about 148 m/pixel (note 50 km scale bar). This view is of the heavily cratered region known as Arabia Terra (image center is at 0.8°N latitude, 43.8°E longitude, and North is toward the top). The western (left) half of this scene shows a dramatic occurrence of martian water-ice clouds. Similar to cirrus clouds on Earth, these clouds form when water vapor in the martian atmosphere freezes into tiny ice particles. The complex structure of these clouds is largely due to interactions between winds and the surface. For example, the parallel bands of clouds (see the lower left portion of the image) result from atmospheric waves induced by winds flowing over obstacles such as crater rims and surface ridges. During this season on Mars (early spring in the northern hemisphere), these types of clouds are often observed in late afternoon (the local time-of-day when this image was captured was about 17:00). The image was taken through EXI’s “blue filter” (437 nanometers); using this filter, clouds appear quite bright against the darker martian surface. This image is a lightly processed “raw version” where artifacts introduced by the camera system have not been removed. In this case, the contrast of the image has been adjusted to enhance the visibility of the clouds.

On 15 March 2021, the Emirates Exploration Imager (EXI) camera system onboard the EMM mission obtained a set of multispectral images of this oblique view of the heavily cratered region known as Arabia Terra. At the time, the Hope spacecraft was approximately 3500 km above the surface of Mars, with the image center being at about 25°N latitude, 48°E longitude. North is toward the top-right. It was early-spring in Mars’ northern hemisphere. Multispectral images (obtained at multiple wavelengths) are very useful when investigating details of the surface and atmosphere of Mars. Longer wavelengths (red images) enhance the appearance of bright and dark surface markings while shorter wavelengths (blue and violet images) enhance atmospheric features (clouds, fogs, and hazes). The image presented here is a false-color composite; an EXI 320 nanometer (ultraviolet) image is used to reveal the extent of water-ice clouds and hazes, while an EXI 673 nanometer (red) image portrays surface features such as craters, dust-covered plains, and dark sand deposits. A color composite where the contrast of the ultraviolet image has been emphasized can further help interpret the relationships between surface and atmospheric features.
In this scene toward the upper-left, one sees bluish early-morning water-ice clouds and hazes above the surface. These form during the night, when water vapor in the martian atmosphere freezes into tiny ice crystals due to low atmospheric temperatures. Ground fogs can collect in topographic depressions, as can be seen in many of the craters in this view. Within a few hours after sunrise (moving toward lower right in the image), the ice particles typically sublimate as the atmosphere warms and the clouds and fogs dissipate. Conditions favorable to formation of nighttime and early-morning water-ice clouds such as these can persist over several months during the late-winter through spring seasons of Mars’ northern hemisphere.

Taken by the Mars Hope probe’s EMUS instrument, the observations show dramatic variations in the concentrations of both atomic oxygen and carbon monoxide in the dayside atmosphere of Mars.

These observations confound scientists’ preconceptions of the distribution of ultraviolet light emitted from the upper atmosphere of Mars, showing vast structures at a range of wavelengths.

These observations, and our previously announced observations of Mars’ discrete aurora, are part of the first data release that went out on Oct 1st . From now onwards, we will be releasing new data sets every three months without embargo and free for use to the community.

The EMM team had expected to observe a relatively uniform emission from oxygen at 130.4 nm across the planet and yet here we are, faced with unpredicted variations of 50% or more in the brightness

These monochromatic images shown here are “Quick Look” products and are generated as part of the EXI data processing pipeline. Their role is intended to offer an efficient way to assess whether the observations were made as planned. Before using these images for scientific analysis, corrections has to be made where possible for any impacts associated with the detector and optics, as well as those that occur as part of being in orbit around Mars such as cosmic rays. The images shown here were taken by EXI using its 635 nm filter during an orbit of Mars on May 5-6, 2021.

On July 18, 2021, the EXI camera system onboard the EMM mission obtained a set of multispectral images of a fully-illuminated hemisphere of Mars – which looks very similar to observations routinely carried out by weather satellites orbiting Earth. At the time the images were taken, the Hope spacecraft was at an altitude of about 20,260 kilometres above the surface; with the view centred at 11.0 °N latitude, -79.4 °E longitude, North is toward the top. In terms of the Martian season, it was late spring in the northern hemisphere.