IAU descriptor term
Lacus in the Solar System
Lacus is the term planetary geologists use for a small dark plain. 114 named features carry it, across 2 of the 14 mapped worlds, the largest being Lacus Somniorum on The Moon at 425 km.
Where they are
The largest lacus anywhere
Ranked across every mapped world, by catalogued diameter.
1Lacus SomniorumThe Moon425 km2Lacus VerisThe Moon383 km3Jingpo LacusTitan240 km4Ontario LacusTitan235 km5Lacus TemporisThe Moon205 km6Hammar LacusTitan200 km7Lacus ExcellentiaeThe Moon198 km8Lacus AutumniThe Moon196 km9Mackay LacusTitan180 km10Muggel LacusTitan170 km11Lacus MortisThe Moon159 km12Lacus TimorisThe Moon154 km13Sionascaig LacusTitan143 km14Lacus SolitudinisThe Moon123 km15Lacus BonitatisThe Moon122 km16Ladoga LacusTitan110 km17Lacus DolorisThe Moon103 km18Bolsena LacusTitan101 km19Lacus FelicitatisThe Moon98.5 km20Neagh LacusTitan98 km21Lacus GaudiiThe Moon88.5 km22Pielinen LacusTitan88 km23Lacus AestatisThe Moon86.4 km24Lacus TenebrarumThe Moon85 km25Sparrow LacusTitan81.4 km26Lacus LenitatisThe Moon78.3 km27Kivu LacusTitan77.5 km28Lacus SpeiThe Moon76.7 km29Lacus OdiiThe Moon72.7 km30Lacus PerseverantiaeThe Moon70.6 km
What they are named after
Naming themes are set per world, so one descriptor can draw on very different sources depending on where it sits. Across all 114 lacus, 78 categories appear.
Latin21United States4Canada3Japan3China2Scotland2Italy2Finland2