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
- 30 September 1921
- Named after
- Arne Asplind, (son of Bror Asplind )
- Alternative designations
- A921 SE · 1927 YD, 1952 DD 2 · 1960 OF, A916 YB · 1921 KF
- Minor planet category
- main-belt · ( outer ) , background
- Observation arc
- 103.03 yr (37,630 d)
- Aphelion
- 3.8813 AU
- Perihelion
- 2.4752 AU
- Semi major axis
- 3.1782 AU
- Orbital period sidereal
- 5.67 yr (2,070 d)
- Mean anomaly
- 86.935 °
- Mean motion
- 0° 10 26.4 / day
- Inclination
- 4.4967°
- Longitude of ascending node
- 58.521°
- Argument of perihelion
- 333.57°
- Mean diameter
- 45.176 ± 0.350 km 53.09 ± 0.75 km 57.42 ± 1.5 km
- Synodic rotation period
- 123.7 ± 0.1 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 45.176
- Orbital period
- 2067.011667064374
Show 14 more facts
- provisional designation
- 1960 OF
- time of discovery or invention
- 1921-09-30
- orbital inclination
- 4.494043385465356
- albedo
- 0.067
- rotation period
- 123.7
- absolute magnitude
- 10.77
- orbital eccentricity
- 0.223958819291293
- semi-major axis of an orbit
- 3.175628328093309
- periapsis
- 2.464418357225549
- apoapsis
- 3.886838298961069
- longitude of ascending node
- 58.44852831496862
- argument of periapsis
- 333.459938427019
- mean anomaly
- 75.27195743880857
- time of periapsis
- 2460568.311071587
Sources (2)
via Wikidata · CC0
~4 min read
Article
959 Arne (prov. designation: A921 SE or 1921 KF) is a background asteroid and slow rotator, approximately 52 kilometers (32 miles) in diameter, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory on 30 September 1921. The X-type asteroid has an exceptionally long rotation period of 123.7 hours. It was named after Arne Asplind, son of Swedish astronomer Bror Asplind (1890–1954).
Orbit and classification