File:51_Nemausa_VLT_(2021),_deconvolved.pdf · Wikimedia Commons · See Wikimedia Commons
Picture of the Day · NASA
Pathfinder on Mars
2026-07-04
On July 4th, 1997, using its own array of fireworks, a parachute, and a cocoon of airbags, the Mars Pathfinder spacecraft bounced like a giant beach ball at least 15 times before it came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. After its then novel airbag-assisted landing sequence was completed, Pathfinder transmitted this color mosaic to mission operators on Earth. In the scene from another world, the Mars Sojourner robot rover is visible in the foreground, crouched on top of the unfolded Pathfinder. About the size of a large house cat, the six-wheeled, solar-powered Sojourner became the first successful Martian rover. Surrounding Pathfinder are deflated airbags and the rock-strewn terrain of the Ares Vallis floodplain. In the distance Martian hills appear against a dusty brownish sky. The Pathfinder lander was subsequently renamed the Carl Sagan Memorial Station.
via NASA APOD
Key facts
- Discovered by
- J. Laurent
- Discovery site
- Nîmes
- Discovery date
- January 22, 1858
- Pronunciation
- / n ɛ ˈ m ɔː s ə /
- Named after
- Nemausus
- Minor planet category
- Main belt
- Adjectives
- Nemausian / n ɛ ˈ m ɔː s i ə n /
- Aphelion
- 2.523 AU (377.381 million km)
- Perihelion
- 2.208 AU (330.360 million km)
- Semi major axis
- 2.365 AU (353.871 million km)
- Orbital period sidereal
- 3.64 a (1328.853 d)
- Mean anomaly
- 316.668°
- Inclination
- 9.972°
- Longitude of ascending node
- 176.168°
- Argument of perihelion
- 2.820°
- Dimensions
- 170×136 km
- Mean diameter
- 150 ± 3 km
- Mass
- (3.9 ± 1.6) × 10 kg , (2.48 ± 0.86) × 10 kg
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Nîmes
- Followed by
- 52 Europa
- Follows
- 50 Virginia
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 138.159
- Orbital period
- 1328.911463703671
- Image
- A642.M1065.shape(1).png
Show 19 more facts
- provisional designation
- A858 BA
- time of discovery or invention
- 1858-01-22
- orbital inclination
- 9.972945325068094
- site of astronomical discovery
- Nîmes
- albedo
- 0.1
- discoverer or inventor
- Joseph Jean Pierre Laurent
- Commons category
- 51 Nemausa
- rotation period
- 7.783
- asteroid spectral type
- C-type asteroid
- absolute magnitude
- 7.73
- orbital eccentricity
- 0.06592722586836675
- semi-major axis of an orbit
- 2.36554790435846
- periapsis
- 2.209593893365378
- apoapsis
- 2.521501915351542
- longitude of ascending node
- 175.8796947337355
- argument of periapsis
- 2.281950966363
- mean anomaly
- 26.54935379295595
- time of periapsis
- 2460902.495164974
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~2 min read
Encyclopedic overview
51 Nemausa is a large main-belt asteroid that was discovered on January 22, 1858, by Joseph Jean Pierre Laurent. Laurent made the discovery from the private observatory of Benjamin Valz in Nîmes, France. The house, at 32 rue Nationale in Nîmes, has a plaque commemorating the discovery. With Laurent's permission, Valz named the asteroid after the Celtic god Nemausus, the patron god and namesake of Nîmes during Roman times.
Based upon its spectrum, this is listed as a C-type asteroid in the Tholen classification taxonomy, and as a Cgh by Bus and Binzel (2002). This indicates a composition similar to carbonaceous chondrite meteorites. Absorption features in the spectrum indicate the presence of phyllosilicates. It may have a water content of about 14%.
Excerpted from Wikipedia’s “51 Nemausa” article, available under the CC BY-SA 4.0 licence.