A grander canyon on Mars

Hebes Chasma, a huge trough on Mars, reflects the Red Planet’s tumultuous and varied past. During the planet’s first billion years, the nearby Tharsis Region bulged with magma, then burst apart, forming enormous chasms such as Hebes (a majority of its 315-kilometer length shown above). More than four times as deep and wide as the Grand Canyon, Hebes may have once been filled with water; some areas have minerals that could have formed only in water’s presence. New images from the European Space Agency’s Mars Express spacecraft show that massive landslides may have shaped and widened the trench since its violent birth.