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Mars' Ionopause: A Matter of Pressures

Holmstrom, Mats; Sánchez-Cano, Beatriz; Mayyasi, Majd +8 more

This study assesses under what circumstances the Martian ionopause is formed on the dayside, both in regions where there are strong crustal magnetic fields and areas where these fields are small (<30 nT). Multiple data sets from three MAVEN dayside deep dip campaigns are utilized between periapsis and 600-1,000 km, as well as solar wind observa…

Martian Ionopause Boundary: Coincidence With Photoelectron Boundary and Response to Internal and External Drivers

Gurnett, D. A.; Morgan, D. D.; Halekas, J. +8 more

The Martian ionopause boundary detected as steep gradients in the local electron density profiles from the Mars Advanced Radar for Subsurface and Ionospheric Sounder on Mars Express is studied individually and statistically and compared to the photoelectron boundary identified by the drop of photoelectron signature due to CO₂ and O mole…

Mars' Ionospheric Interaction With Comet C/2013 A1 Siding Spring's Coma at Their Closest Approach as Seen by Mars Express

Leblanc, François; Cowley, Stanley W. H.; Cardesín-Moinelo, Alejandro +9 more

On 19 October 2014, Mars experienced a close encounter with Comet C/2013 A1 Siding Spring. Using data from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) on board Mars Express (MEX), we assess the interaction of the Martian ionosphere with the comet's coma and possibly magnetic tail during the orbit of their closest approa…

Mars Express Observations of Cold Plasma Structures in the Martian Magnetotail

Lester, M.; Edberg, N. J. T.; Andrews, D. J. +5 more

We present observations from five Mars Express (MEX) orbits in September 2016 while the spacecraft passed through the Martian induced magnetotail at altitudes up to 3,500 km. On these orbits, the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument was operated in Active Ionospheric Sounding (AIS) mode at much higher alti…

Observations of Sounder Accelerated Electrons by Mars Express

Barabash, S.; Winningham, J. D.; Frahm, R. A. +5 more

The electron sensor of the Analyzer of Space Plasmas and Energetic Atoms experiment detects accelerated electrons during pulses of radio emissions from the powerful topside sounder: the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) on board the Mars Express spacecraft. Accelerated electrons are observed at energies up to 400 …