Impact Basin
An enormous impact structure, hundreds to thousands of kilometres across, formed by a giant early impact — often multi-ringed and later flooded by lava, as with the lunar maria.
In brief
A very large, often multi-ringed, impact structure.
Examples of this feature
- Caloris PlanitiaSurface featureMercury · ≈ 1,550 km across
One of the largest impact basins in the Solar System, on Mercury, so violent that its antipode is marked by chaotic 'weird terrain' shaken up by the focused seismic waves.
- Hellas PlanitiaSurface featureMars · ≈ 2,300 km across, ~7 km deep
One of the largest visible impact basins in the Solar System and the lowest point on Mars, deep enough that the atmospheric pressure at its floor can allow liquid water briefly.
- RheasilviaSurface feature4 Vesta · ≈ 500 km across
An enormous impact basin covering much of the south pole of the asteroid Vesta, with a central peak among the tallest in the Solar System. Its excavation launched the HED meteorites.
- ValhallaSurface featureCallisto · rings span ~3,800 km
A giant multi-ring impact structure on Callisto — concentric rings of ridges rippling out from a bright central plain across the most heavily-cratered surface in the Solar System.
Knowledge connections
- Group includesHellas Planitia
- Group includesCaloris Planitia
- Group includesRheasilvia
- Group includesValhalla
- Group includesSouth Pole–Aitken Basin
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.