Space Exploration & Science Missions

Study finds ancient ocean once covered roughly half of Mars

Researchers at the University of Bern present new evidence that an ocean once covered about half of Mars’ surface, reshaping estimates of early water distribution. The result refocuses where sedimentary deposits and shoreline-associated biosignatures are most likely to be preserved and sampled.

Discovered 2026-01-13T11:27:46.415402-08:00 | 2026-01-13T11:27:46.415402-08:00

Briefing

What Hype is tracking

The finding argues an ocean covered roughly 50% of Mars’ surface, shifting priority toward coastal and shoreline sediments that are most likely to preserve biosignatures and altering landing-site selection and sampling strategies.
It strengthens the case for targeting sheltered, ice-bearing or cave-associated environments as long-term preservers of organics, complementing recent detections of skylights and water-ice signatures.
The quantitative ‘‘half-planet’’ constraint will be incorporated into climate and hydrology models that define mission science objectives and instrument requirements for future Mars exploration.

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