Tiny to Vast
Planetary terrain experiment3D globe · Elevation map

Waterlines on Other Worlds

Choose a world and move a hypothetical liquid level across its terrain. Compare the resulting patterns on a globe or flat map.

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One more perspective

Keep exploring the scale

Every toy changes one assumption. Try another and see what moves.

Fig. 01

Planetary terrain

Mars Sea Level Simulator

Give Mars a hypothetical ocean and watch its lowlands fill as you move the waterline across its terrain.

Fig. 02

Planetary scale

Country Size on Planets

Compare countries on a true globe, then place them on worlds across the solar system.

Five bodies, five elevation datasets

What the waterline means

The map colors terrain lower than the height you choose. A closed crater can turn blue even if no water could reach it. Each world uses its own reference sphere for zero metres, so a +1,000 m setting does not represent the same liquid volume on all five.

Rocky worlds

Magellan radar measured Venus beneath its clouds. MESSENGER mapped Mercury, LOLA measured the Moon, and Dawn mapped Ceres. The Moon's dark maria are lava plains. None of these four worlds has a present-day surface water ocean.

Titan is different

Titan has real methane and ethane seas. The Cassini topography used here is sparse, however: about 90% of its global surface model is interpolated. Treat the blue threshold as an experiment, not the observed shoreline.

Data and limits

Each world loads a self-hosted overview below 20 MiB. Tiles stop at zoom level 3; zooming farther enlarges the same pixels. Web Mercator tiles omit the last few degrees around each pole. The Venus, Mercury, and Moon basemaps are illustrative surface images.

Mars Sea Level SimulatorEarth Sea Level Rise Map

Waterline questions

Do the blue areas show real oceans?

No. Every blue pixel lies below the selected height. The map does not test whether liquid exists, connects to other areas, or could remain stable there.

What does zero metres mean on each world?

Zero is the reference sphere used by that body's elevation dataset. These spheres have different radii, so the same height setting is not the same water volume on different worlds.

Are Titan's methane seas shown accurately?

No. Titan has real methane and ethane seas, but most of the global topography in this map is interpolated from sparse Cassini radar observations. Blue is only a hypothetical height threshold.

This map applies a height threshold to present-day terrain. It does not reconstruct ancient climates or forecast a future ocean.