OceanOceanography
Mars is better mapped than Earth's own seafloor.
Essentially all of Mars has been mapped from orbit in high resolution, but only about a quarter of Earth's seafloor has been surveyed to comparable detail. The rest is estimated from satellite gravity measurements blurry enough to hide entire underwater mountains.
Step by step
- Orbiters have imaged essentially the whole surface of Mars in high resolution.
- Only about a quarter of Earth's seafloor is mapped to comparable standards.
- The rest is guessed from satellite gravity — blurry enough to hide whole mountains.
Source
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