This unnamed crater on Mars is filled with material of a ‘wrinkled’ appearance. This texture usually implies that material once flowed here, and likely comprised a mixing of rocks, ice or frost, and other soil deposits. The wrinkles seem to have formed in parallel layers which is consistent with material settling onto the crater floor, perhaps in different episodes. Volatiles such as water ice could still be mixed with the rocky sediments to create the observed texture.
The image was captured by the CaSSIS camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter on 3 July 2019. The image is centred at 35ºN/169.5ºE. North is up.
This image captures prominent bright and dark streaks on slopes in the ancient Locras Vallis region on Mars.
The image was taken in the early martian morning on 20 June 2019 by the CaSSIS camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter.
The brighter streaks are facing northeast; their photometric characteristics may depend on lighting geometry. The exact relationship between bright and dark slope streaks is still debated but the leading theory suggests that are formed by a dry avalanching process.
The image is centred at 10.6ºN/41.6ºE. North is up.
Gale Crater, home of NASA's Curiosity Rover, is approximately 150 km in diameter and located near the boundary between the southern highlands and northern lowlands of Mars. The crater contains a massive central mound that contains a kilometres-thick layered sequence of sedimentary rocks that provide evidence for a changing climate over the planet’s history. Studies indicate that it transitioned from wetter conditions in which water-bearing minerals formed, to the drier climate conditions observed today.
The exposed layers seen in this image, taken by the CaSSIS camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter, are located on the west side of the Gale crater central mound. This section belongs to the so-called ‘Lower Formation’, which is characterised by abundant signatures of the presence of water as observed by the CRISM imaging spectrometer onboard NASA’s Mars Reconnaissance Orbiter. These transition from sulphate-bearing, to clay-sulphate mixtures, to sulphate-bearing rocks in the highest parts of the formation. The transitions are reflected here in the changing colours observed by CaSSIS.
The image is centred at 5.2ºS/137.2ºE and was taken on 20 July 2019. North is up.
This colourful image from the CaSSIS camera onboard the ESA/Roscosmos ExoMars Trace Gas Orbiter shows an area within Oyama Crater, which is near Mawrth Vallis on Mars.
The lighter tones are probably related to clay minerals that have been identified across the region by the OMEGA instrument on ESA’s Mars Express and by the CRISM instrument on NASA’s Mars Reconnaissance Orbiter. The CaSSIS data has higher spatial resolution and, in combination with the spectrometer, can help look at spatial relationships between the different mineral species. This image is particularly interesting because of the distinct layers exposed in the walls of small crater at the top of the image, giving us a window back in time. Areas like these are frequently ranked highly as potential landing sites for missions because of the influence of water and as such their potential for preservation of traces of past life.
The image is centred at 23.4ºN/340ºE. North is up. The image was taken on 13 June 2019.
This captivating image was taken in the north polar region of Mars by the ESA/Roscosmos ExoMars Trace Gas Orbiter’s CaSSIS camera.
Dunes come in various characteristic shapes on Mars just as on Earth, providing clues about the prevailing wind direction. Monitoring them over time also gives us a natural laboratory to study how dunes evolve, and how sediments in general are transported around the planet.
During winter in the polar regions, a thin layer of carbon dioxide ice covers the surface and then sublimates – turns directly from ice into vapour – with the first light of spring. In the dune fields, this springtime defrosting occurs from the bottom up, trapping gas between the ice and the sand. As the ice cracks, this gas is released violently and carries sand with it, forming the dark patches and streaks observed in this CaSSIS image.
The image also captures ‘barchan’ dunes – the crescent or U-shaped dunes seen in the right of the image – as they join and merge into barchanoid ridges. The curved tips of the barchan dunes point downwind. The transition from barchan to barchanoid dunes tells us that secondary winds also play a role in shaping the dune field.
The image is centred at 74.46ºN/348.3ºE. The image was taken on 25 May 2019.
New images and results from the ESA/Roscosmos ExoMars Trace Gas Orbiter’s suite of scientific instruments will be discussed this week at the joint meeting of the European Planetary Science Congress and the Division of Planetary Sciences in Geneva, Switzerland, this week. Follow the conversation on Twitter via #EPSCDPS2019.