Bright material litters the floor of a trough in Noctis Labyrinthus, a maze-like region of deep valleys near one of Mars's volcanic plains.
The recently released image was snapped by NASA's Mars Reconnaissance Orbiter. Other data from the spacecraft suggest that the material is hydrated—that is, it contains water in its atomic structure.
Scientists think the hydrated material could have formed long ago, either from subsurface water upwelling in the trough or from surface ice melting from the heat of nearby volcanic activity.
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