Juventae Chasma, just north of Valles Marineris, is notable for several reasons: it is an otherworldly size-box canyon, and shares a name with the mythological Fountain of Youth.

This image, from Juventae Chasma’s southern extent, captures the extraordinary visual softness of the sand on the bottom of the canyon. Unlike other places in Juventae Chasma where ripples and more bedrock landforms are visible, in this scene we can identify peaks arising from a base of smooth materials. Rather than the sand being grouped in well-behaved, Star-Trek-communicator-badge-shaped barchan dunes, the sand blankets the full surface below the two peaks captured here. The source of this sand is linked to the chasma’s complex geologic history, which likely includes a combination of icy, watery, and windy processes.

Written by: Margaret Landis  (2 July 2026)