Search Publications
The volcanic history of Mars: High-resolution crater-based studies of the calderas of 20 volcanoes
Hynek, Brian M.; Robbins, Stuart J.; di Achille, Gaetano
Determining absolute surface ages for bodies in the Solar System is, at present, only possible for Earth and Moon with radiometric dating for both bodies and biologic proxies such as fossils for Earth. Relative ages through cratering statistics are recognized as one of the most reliable proxies for relative ages, calibrated by lunar geologic mappi…
Sequence and timing of conditions on early Mars
Head, James W.; Fassett, Caleb I.
The geological record of early Mars displays a variety of features that indicate fundamental differences from more recent conditions. These include evidence for: (1) widespread aqueous alteration and phyllosilicate formation, (2) the existence of an active magnetic dynamo, (3) the erosion of extensive valley networks, some thousands of kilometers …
Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars
Werner, S. C.; Tanaka, K. L.
For the boundaries of each chronostratigraphic epoch on Mars, we present systematically derived crater-size frequencies based on crater counts of geologic referent surfaces and three proposed "standard" crater size-frequency production distributions as defined by (a) a simple -2 power law, (b) Neukum and Ivanov, (c) Hartmann. In turn, these crater…
Heavy ion escape from Mars, influence from solar wind conditions and crustal magnetic fields
Barabash, Stas; Lundin, Rickard; Nilsson, Hans +5 more
We have used more than 4 years of Mars Express ion data to estimate the escape of heavy ions ( O+,O2+ and CO2+) from Mars. To take the limited field of view of the instrument into account, the data has been binned into spatial bins and angular bins to create average distribution functions for different positions in the near Mars space. …
Stratigraphy, mineralogy, and origin of layered deposits inside Terby crater, Mars
Mangold, N.; Le Mouélic, S.; Bibring, J. -P. +13 more
The 174 km diameter Terby impact crater (28.0°S-74.1°E) located on the northern rim of the Hellas basin displays anomalous inner morphology, including a flat floor and light-toned layered deposits. An analysis of these deposits was performed using multiple datasets from Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbit…
Evidence for weathering on early Mars from a comparison with terrestrial weathering profiles
Mangold, N.; Dehouck, E.; Gaudin, A.
Phyllosilicates on Mars are widespread in the ancient crust suggesting the presence of liquid water at the martian surface and therefore warmer conditions during its early history. However, the role of the ancient climate in the alteration process, which produced these phyllosilicates, remains under debate, because similar mineral assemblages can …
Sorted clastic stripes, lobes and associated gullies in high-latitude craters on Mars: Landforms indicative of very recent, polycyclic ground-ice thaw and liquid flows
Balme, M. R.; Conway, S. J.; Grindrod, P. M. +1 more
Self-organised patterns of stone stripes, polygons, circles and clastic solifluction lobes form by the sorting of clasts from fine-grained sediments in freeze-thaw cycles. We present new High Resolution Imaging Science Experiment (HiRISE) images of Mars which demonstrate that the slopes of high-latitude craters, including Heimdal crater - just 25 …
Sulfates and iron oxides in Ophir Chasma, Mars, based on OMEGA and CRISM observations
Neukum, Gerhard; Combe, Jean-Philippe; Gross, Christoph +5 more
We investigate the sulfate and iron oxide deposits in Ophir Chasma, Mars, based on short-wave infrared data from the Compact Reconnaissance Imaging Spectrometer for Mars - CRISM and from the Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité - OMEGA. Sulfates are detected mainly in two locations. In the valley between Ophir Mensa an…
Multitemporal observations of identical active dust devils on Mars with the High Resolution Stereo Camera (HRSC) and Mars Orbiter Camera (MOC)
Neukum, G.; Reiss, D.; Zanetti, M.
Active dust devils were observed in Syria Planum in Mars Observer Camera - Wide Angle (MOC-WA) and High Resolution Stereo Camera (HRSC) imagery acquired on the same day with a time delay of ∼26 min. The unique operating technique of the HRSC allowed the measurement of the traverse velocities and directions of motion. Large dust devils observed in …
Annual survey of water vapor behavior from the OMEGA mapping spectrometer onboard Mars Express
Maltagliati, Luca; Bibring, Jean-Pierre; Forget, Francois +4 more
We present here the annual behavior of atmospheric water vapor on Mars, as observed by the OMEGA spectrometer on board Mars Express during its first martian year. We consider all the different features of the cycle of water vapor: temporal evolution, both at a seasonal and at a diurnal scale; longitudinal distribution; and the vertical profile, th…