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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
- Observation arc
- 86.00 yr (31,410 d)
- Aphelion
- 2.9991 AU
- Perihelion
- 2.7218 AU
- Semi major axis
- 2.8604 AU
- Orbital period sidereal
- 4.84 yr (1,767 d)
- Mean anomaly
- 272.19 °
- Mean motion
- 0° 12 13.32 / day
- Inclination
- 1.7799°
- Longitude of ascending node
- 184.26°
- Argument of perihelion
- 249.56°
- Mean diameter
- 12.43 ± 1.13 km , 15.15 ± 1.17 km
- Synodic rotation period
- 5.2712 ± 0.0007 h
- Geometric albedo
- 0.147 , 0.315
- Spectral type
- S (assumed)
- Absolute magnitude h
- 11.4 , 11.80
- Discovered by
- G. van Biesbroeck
- Discovery site
- Yerkes Obs.
- Discovery date
- 12 January 1923
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Forest Ray Moulton
- Followed by
- 994 Otthild
- Follows
- 992 Swasey
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 12.433
- Orbital period
- 1767.022260382847
Show 17 more facts
- discoverer or inventor
- George Van Biesbroeck
- site of astronomical discovery
- Yerkes Observatory
- provisional designation
- A923 AB
- time of discovery or invention
- 1923-01-12
- orbital inclination
- 1.782002015006205
- albedo
- 0.315
- rotation period
- 5.2712
- absolute magnitude
- 11.43
- orbital eccentricity
- 0.04702300002849138
- semi-major axis of an orbit
- 2.860415103426377
- periapsis
- 2.725909803936461
- apoapsis
- 2.994920402916292
- longitude of ascending node
- 184.2060417464425
- argument of periapsis
- 244.6927259541836
- mean anomaly
- 127.2566094031946
- time of periapsis
- 2460375.8742733435
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~3 min read
Encyclopedic overview
993 Moultona, provisional designation 1923 NJ, is a Koronian asteroid from the outer regions of the asteroid belt, approximately 14 kilometers (8.7 miles) in diameter. It was discovered on 12 January 1923, by astronomer George Van Biesbroeck at the Yerkes Observatory in Williams Bay, Wisconsin, in the United States. The likely elongated asteroid has a rotation period of 5.3 hours. It was named after American astronomer Forest Ray Moulton.
Orbit and classification
Excerpted from Wikipedia’s “993 Moultona” article, available under the CC BY-SA 4.0 licence.