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
- K. Reinmuth
- Discovery site
- Heidelberg Obs.
- Discovery date
- 31 August 1929
- Named after
- Arabian Peninsula
- Alternative designations
- 1929 QC · 1955 EC
- Minor planet category
- main-belt · ( outer ) , background
- Observation arc
- 87.58 yr (31,987 days)
- Aphelion
- 3.6412 AU
- Perihelion
- 2.7221 AU
- Semi major axis
- 3.1816 AU
- Orbital period sidereal
- 5.68 yr (2,073 days)
- Mean anomaly
- 195.98 °
- Mean motion
- 0° 10 25.32 / day
- Inclination
- 9.5447°
- Longitude of ascending node
- 336.19°
- Argument of perihelion
- 313.37°
- Dimensions
- 29.01 ± 0.84 km , 29.113 ± 4.433 km , 55.67 km (calculated)
- Synodic rotation period
- 15.225 ± 0.005 h
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Arabian Peninsula
- Followed by
- 1158 Luda
- Follows
- 1156 Kira
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 29.113
- Orbital period
- 2076.176991966624
Show 17 more facts
- discoverer or inventor
- Karl Wilhelm Reinmuth
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- 1955 EC
- time of discovery or invention
- 1929-08-31
- orbital eccentricity
- 0.1432401596529439
- orbital inclination
- 9.54847708908238
- periapsis
- 2.728787598059245
- apoapsis
- 3.64122992506338
- semi-major axis of an orbit
- 3.185008761561313
- mean anomaly
- 358.165719203004
- longitude of ascending node
- 336.0709170473498
- argument of periapsis
- 312.0085446007327
- absolute magnitude
- 10.01
- albedo
- 0.247
- rotation period
- 11.55
- time of periapsis
- 2461011.078587743
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~3 min read
Encyclopedic overview
1157 Arabia, provisional designation 1929 QC, is an asteroid from the outer regions of the asteroid belt, approximately 29 kilometers in diameter. Astronomer Karl Reinmuth discovered it at the Heidelberg Observatory in southwest Germany on 31 August 1929. The asteroid was named for the Arabian Peninsula.
Orbit and classification
Excerpted from Wikipedia’s “1157 Arabia” article, available under the CC BY-SA 4.0 licence.