The new data from the orbiter suggest that at some point in the planet's history, the flat northern lowlands suffered blistering heat, experienced rapid cooling, then drowned under floods that formed an ocean. Channels beneath the northern lowlands could have flowed from Valles Marineris and the Chryse and Kasei Valles regions, NASA scientists said. Water flowing on the surface or underground in channels and later buried by sediments could explain the appearance of the features. Their large size suggests that part or parts of the northern lowlands rapidly filled with water. Cutaway of the martian interior generated from data gathered by Mars Global Surveyor.
Blues indicate thin areas of crust, while reds and whites indicate thicker areas.
The prospect of large amounts of past water excites planetary scientists, who wonder if the red planet ever was alive. Two distinct crust regions Measuring gravity and topography, the orbiter's laser instruments revealed much about the crust of the red planet. The thick, solid layer offers geologic clues about interior melting and heat loss over time. The orbiter began mapping the red planet the following year. All Rights Reserved.