Mare Tranquillitatis
Location: ·
The 'Sea of Tranquility' — its basalt carries a faint bluish tint from titanium-rich lava.
The mare has a measurably bluer tone than the rest of the Moon, and the cause is titanium. Apollo 11 returned basalts with up to about 13 percent titanium dioxide, far more than anyone expected from a lava, and TiO2 content is what the colour ratio maps. Reflectance photography of the near side is, in this respect, a chemical map.
In 2024 a reanalysis of Lunar Reconnaissance Orbiter radar data showed that the Mare Tranquillitatis pit opens into a cave conduit tens of metres long - the first lunar cave demonstrated rather than inferred, and evidence that lava tubes survive beneath the maria.
Sunrise
Sunset
Sunrise and sunset on Mare Tranquillitatis
| Event | Time | Lit |
|---|---|---|
| Computing… | ||
- Sunrise / Sunset: at the feature's centre (IAU Gazetteer of Planetary Nomenclature).
- Lit: the illuminated fraction of the Moon's disc at that moment.
Further info
Official record from the IAU Gazetteer of Planetary Nomenclature: Mare Tranquillitatis
Wikipedia: Mare Tranquillitatis