Overview
- Researchers reporting in Nature identify a broad, low-slope band in Mars’ northern lowlands that they interpret as a coastal shelf.
- The team used NASA’s Mars Global Surveyor topography with an Earth-tested slope and curvature method, arguing shelves preserve ocean signals better than shifting shorelines.
- Within the low-slope zone they mapped deltas, coastal deposits, and river-built sediments that fit what geologists expect on a marine shelf.
- The evidence points to a long-lived ocean on early Mars that lasted millions of years and may have covered about a third of the planet’s surface.
- The authors say future rovers could confirm the shelf by finding layered rocks and wave-made textures, a step that could guide life-detection targets and landing plans.