Search Publications
Evidence of Ice-Rich Layered Deposits in the Medusae Fossae Formation of Mars
Orosei, Roberto; Plaut, Jeffrey J.; Campbell, Bruce A. +4 more
Subsurface reflectors in radar sounder data from the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument aboard the Mars Express spacecraft indicate significant dielectric contrasts between layers in the Martian Medusae Fossae Formation (MFF). Large density changes that create dielectric contrasts are less likely in deposits of …
Revising the Basal Permittivity of the South Polar Layered Deposits of Mars With a Surficial Dust Cover
Kofman, W.; Hérique, A.; Grima, C. +1 more
Bright basal reflections from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) have been proposed to be consistent with permittivities characteristic of a wet material beneath the south polar layered deposits (SPLD). The characterization of a recently formed impact crater highlight the existence of a several meters thick ice…
A Tectonic Origin for the Largest Marsquake Observed by InSight
Wilson, Colin; Lucas, Antoine; Tirsch, Daniela +23 more
The S1222a marsquake detected by InSight on 4 May 2022 was the largest of the mission, at MwMa 4.7. Given its resemblance to two other large seismic events (S1000a and S1094b), which were associated with the formation of fresh craters, we undertook a search for a fresh crater associated with S1222a. Such a crater would be exp…
Global Spatial Distribution of Hack's Law Exponent on Mars Consistent With Early Arid Climate
Luo, W.; Howard, A. D.; Craddock, R. A. +2 more
Widespread valley networks (VNs) on Mars and other evidence point to an early warm and wet climate. However, ongoing debates still exist about VN's formation processes and associated climatic conditions. The power law relationship between basin length and area (Hack's Law) can be diagnostic of different fluvial processes related to climatic condit…
The Basal Detectability of an Ice-Covered Mars by MARSIS
Mouginot, J.; Kofman, W.; Hérique, A. +2 more
The detection of anomalously strong relative basal reflectivity beneath the Martian South Polar Layered Deposits (SPLD) from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) has led to hypotheses suggesting the presence of basal materials such as liquid water. Here, we propose a forward approach to assess whether such a high…
Mars-Ward Ion Flows in the Martian Magnetotail: Mars Express Observations
Barabash, Stas; Nilsson, Hans; Rong, Zhaojin +10 more
We investigate Mars-ward planetary ions (O+ and O2+) in the Martian magnetotail that potentially reduce the amount of escaping ions. The global properties of Mars-ward flows in the Martian magnetotail are characterized, based on over 13-years of ion data (May 2007-December 2020) collected by the Analyzer of Space P…
Paleolake Inlet Valley Formation: Factors Controlling Which Craters Breached on Early Mars
Fassett, C. I.; Bamber, Emily R.; Goudge, T. A. +2 more
The ancient surface of Mars is dominated by degraded impact craters with reduced or eliminated rim relief. Some degraded craters have an inlet valley, while many remain fluvially isolated. Despite controlling Martian fluvial connectivity, few constraints exist on why some—but not all—degraded craters possess inlets. We compared a suite of properti…
Geologic Context of the Bright MARSIS Reflectors in Ultimi Scopuli, South Polar Layered Deposits, Mars
Landis, M. E.; Whitten, J. L.
Radar-bright basal reflectors have been detected below the South Polar Layered Deposits (SPLD), using Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) data and have an exciting but controversial interpretation: liquid water from subglacial lakes. We mapped the surface of the SPLD immediately above and surrounding the putative la…
MAVEN Proton Observations Near the Martian Moon Phobos: Does Phobos Backscatter Solar Wind Protons?
André, N.; Halekas, J. S.; Fowler, C. M. +7 more
ESA's Mars Express (MEX) may have observed twice solar wind protons backscattered by Phobos. However, these detections remain uncertain and call for an independent confirmation. Here, we analyze the proton measurements collected by the Suprathermal And Thermal Ion Composition experiment onboard NASA's Mars Atmosphere and Volatile EvolutioN mission…
Strong MARSIS Radar Reflections From the Base of Martian South Polar Cap May Be Due to Conductive Ice or Minerals
Putzig, N. E.; Bierson, C. J.; Tulaczyk, S. +1 more
Recent results from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument have been interpreted as evidence of subsurface brine pooled beneath 1.3 km-thick South Polar Layered Deposit (SPLD). This interpretation is based on the assumption that the regionally high strength of MARSIS radar reflections from the base of th…