File:331_Etheridgea.png · 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
- Auguste Charlois
- Discovery date
- 1 April 1892
- Pronunciation
- / ˌ ɛ θ ə ˈ r ɪ dʒ i ə /
- Named after
- Possibly Robert Etheridge
- Minor planet category
- Main belt
- Observation arc
- 123.95 yr (45,274 d)
- Aphelion
- 3.32623 AU (497.597 Gm )
- Perihelion
- 2.72055 AU (406.988 Gm)
- Semi major axis
- 3.02339 AU (452.293 Gm)
- Orbital period sidereal
- 5.26 yr (1,920.2 d)
- Mean anomaly
- 88.5392 °
- Mean motion
- 0° 11 14.939 / day
- Inclination
- 6.05385°
- Longitude of ascending node
- 22.0346°
- Argument of perihelion
- 333.055°
- Dimensions
- 74.92 ± 2.7 km
- Synodic rotation period
- 25.315 h (1.0548 d )
- Geometric albedo
- 0.0447 ± 0.003
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 332 Siri
- Follows
- 330 Adalberta
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 74.92
- Orbital period
- 1922.52619369202
- Image
- Орбита астероида 331.png
Show 18 more facts
- discoverer or inventor
- Auguste Charlois
- site of astronomical discovery
- Nice Observatory
- provisional designation
- A892 GA
- time of discovery or invention
- 1892-04-01
- asteroid spectral type
- C-type asteroid
- orbital inclination
- 6.035604478516255
- albedo
- 0.0447
- rotation period
- 25.315
- absolute magnitude
- 9.94
- orbital eccentricity
- 0.095198247758637
- semi-major axis of an orbit
- 3.02586275586031
- periapsis
- 2.737805923544288
- apoapsis
- 3.313919588176331
- longitude of ascending node
- 21.83109315595486
- argument of periapsis
- 334.2998078342903
- mean anomaly
- 3.85617774512045
- time of periapsis
- 2460979.906659104
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~2 min read
Encyclopedic overview
331 Etheridgea is a large main belt asteroid. It was discovered by Auguste Charlois on 1 April 1892 in Nice. The meaning of the name is unknown. This asteroid is orbiting the Sun at a distance of 3.02 AU with a period of 5.26 years and an eccentricity (ovalness) of 0.10. The orbital plane is tilted at an angle of 6.05° to the plane of the ecliptic.
Analysis of the asteroid light curve generated from photometric data collected in 2015 provided a rotation period of 25.315±0.001 h. This result is completely different from the previous rotation period estimates. It is a low albedo, carbonaceous C-type asteroid and spans a girth of 74.9±2.7 km.
Excerpted from Wikipedia’s “331 Etheridgea” article, available under the CC BY-SA 4.0 licence.