MARSIS

MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) is a low frequency, pulse-limited radar sounder and altimeter developed by the University of Rome La Sapienza and Alenia Spazio (today Thales Alenia Space Italy).

[2] It features ground-penetrating radar capabilities, which uses synthetic aperture technique and a secondary receiving antenna to isolate subsurface reflections.

The deployment of the booms was a critical and highly complex task, requiring effective inter-agency cooperation between ESA, NASA, industry partners, and public Universities.

[9] A 2012 paper by the MARSIS team measured a difference between the dielectric constant of the northern and southern high-latitude regions.

[11] Using MARSIS data, 22 Italian scientists reported in July 2018 the discovery of a subglacial lake on Mars, 1.5 km (0.93 mi) below the southern polar ice cap, and extending horizontally about 20 km (12 mi), the first known stable body of water on Mars.

Illustration of Mars Express with MARSIS antenna deployed
Size of the MARSIS antenna (horizontal line) compared to the spacecraft and a human silhouette