Mare Tranquillitatis (Moon)
Data as of 2026-10-23
What it is
- Type
- Mare, maria
- IAU definition
“Sea”; on the Moon, low albedo, relatively smooth plain, generally of large extent; on Mars, dark albedo areas of no known geological significance; on Titan, large expanses of dark materials thought to be liquid hydrocarbons
- Diameter
- 875.7 km, 50 % of the radius of its body
- Centre
- 8.35° N, 30.84° east (planetocentric latitude, east longitude from 0 to 360°, the IAU convention)
- Name adopted
- 1935
- Origin of the name
"Sea of Tranquility."
Quoted in English, as the IAU publishes it.
In Galaxy
Opens its body in the application, the camera turned towards Mare Tranquillitatis.
Observed by
Instruments whose footprint touches this formation, counted by the PDS Orbital Data Explorer (data frozen on September 29, 2026). A footprint that touches it is not a study of it.
| Mission and instrument | Products | First | Last |
|---|---|---|---|
| Lunar Orbiter · 24 Inch Focal Length Camera | 138 | February 16, 1967 | August 12, 1967 |
| Lunar Orbiter · 80mm Focal Length Camera | 28 | August 11, 1967 | August 12, 1967 |
| Clementine · Ultraviolet/Visible Camera | 8,899 | February 24, 1994 | April 22, 1994 |
| Clementine · High Resolution Camera | 7,383 | February 24, 1994 | April 24, 1994 |
| Clementine · Near Infrared Camera | 5,123 | February 24, 1994 | April 22, 1994 |
| Clementine · Long Wavelength Infrared Camera | 3,571 | February 24, 1994 | April 24, 1994 |
| Arecibo Observatory/National Radio Astronomy Observatory · Earth-based Arecibo Radio Telescope/Robert C. Byrd Green Bank Telescope | 77 | August 8, 2004 | May 14, 2013 |
| JAXA SELENE/KAGUYA Main Orbiter · High Definition Television | 17,166 | November 18, 2007 | June 2, 2009 |
| JAXA SELENE/KAGUYA Main Orbiter · Terrain Camera | 10,668 | December 14, 2007 | June 3, 2009 |
| JAXA SELENE/KAGUYA Main Orbiter · Lunar Radar Sounder | 1,555 | December 15, 2007 | September 1, 2008 |
| JAXA SELENE/KAGUYA Main Orbiter · Laser Altimeter | 38 | December 30, 2007 | October 26, 2008 |
| JAXA SELENE/KAGUYA Main Orbiter · Multiband Imager | 14,551 | March 20, 2008 | October 12, 2008 |
| ISRO's Chandrayaan-1 · Moon Mineralogy Mapper | 156 | January 5, 2009 | July 31, 2009 |
| ISRO's Chandrayaan-1 · Forerunner (aka "Mini-RF" or "Mini-SAR") | 2,354 | February 15, 2009 | August 24, 2009 |
| Lunar Reconnaissance Orbiter · DIVINER Lunar Radiometer Experiment | 20,511 | July 5, 2009 | June 9, 2026 |
| Lunar Reconnaissance Orbiter · Lunar Reconnaissance Orbiter Camera | 57,885 | July 10, 2009 | June 10, 2026 |
| Lunar Reconnaissance Orbiter · Lunar Orbiter Laser Altimeter | 2,604 | July 13, 2009 | June 15, 2019 |
| Lunar Reconnaissance Orbiter · MINI-RF LRO | 1,820 | July 25, 2009 | May 12, 2026 |
| Korea Pathfinder Lunar Orbiter · Shadow Camera | 144 | February 16, 2023 | August 29, 2024 |
Sources
International Astronomical Union Working Group for Planetary System Nomenclature, Gazetteer of Planetary Nomenclature, read on October 23, 2026. Feature page: https://planetarynames.wr.usgs.gov/Feature/3691
Type definitions: IAU Descriptor Terms, read on October 17, 2026. https://planetarynames.wr.usgs.gov/DescriptorTerms