We have more accurate maps of the surface of Mars and the Moon than of the floor of our own ocean — less than a third of the seabed has been measured in real detail, meaning most of the largest landscape on the planet has never been surveyed up close b - Space Daily

Earth’s oceans still remain less precisely mapped than the surfaces of the Moon and Mars, highlighting a striking gap in exploration priorities. According to the report, less than one-third of the seabed has been measured in high detail, meaning most of the planet’s largest landscape has never been closely surveyed.

The comparison is especially stark in the Pacific, where elevation data for the ocean floor is described as less complete than mapping of the Moon. That means scientists have better terrain information for distant worlds than for vast areas beneath Earth’s own oceans.

The article says this shortfall is not mainly about a lack of technical capability. Instead, it points to a mismatch in funding, attention and long-term commitment to ocean mapping. The issue was highlighted on 20 April 2026 at the International Hydrographic Organization’s assembly in Monaco, where the need for more detailed seabed data was brought into focus.

More accurate seabed maps matter for science, navigation, hazard monitoring and understanding the planet itself. The report suggests that closing the ocean floor mapping gap would not require a breakthrough in technology so much as a stronger global effort to survey an environment that still remains largely unseen.