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
- 26 February 1941
- Named after
- Siegfried Böhme (astronomer)
- Alternative designations
- 1941 DF · 1930 UJ, 1942 JC · 1947 RB, 1951 MN · 1956 TM, A917 SO
- Minor planet category
- main-belt · ( middle )
- Observation arc
- 99.22 yr (36,239 days)
- Aphelion
- 3.0198 AU
- Perihelion
- 2.2915 AU
- Semi major axis
- 2.6557 AU
- Orbital period sidereal
- 4.33 yr (1,581 days)
- Mean anomaly
- 68.735 °
- Mean motion
- 0° 13 39.72 / day
- Inclination
- 5.7171°
- Longitude of ascending node
- 199.80°
- Argument of perihelion
- 127.21°
- Dimensions
- 25.16 ± 7.20 km , 26.05 ± 8.68 km , 26.56 km (derived) , 28.842 ± 0.383 km , 29.351 ± 0.105 km , 29.38 ± 0.41 km
- Synodic rotation period
- 56.65 ± 0.04 h , 56.81 ± 0.01 h , 56.8129 ± 0.1652 h
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- Q141730
- Follows
- Q141701
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 29.351
- Orbital period
- 1580.546187473832
- Image
- 001632-asteroid shape model (1632) Sieböhme.png
Show 18 more facts
- discoverer or inventor
- Karl Wilhelm Reinmuth
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A917 SO
- time of discovery or invention
- 1941-02-26
- orbital eccentricity
- 0.1360909999198726
- orbital inclination
- 5.718802903812322
- periapsis
- 2.2940726902055
- apoapsis
- 3.016840125826572
- semi-major axis of an orbit
- 2.655456408016036
- mean anomaly
- 32.68446087170109
- longitude of ascending node
- 199.7019648181804
- argument of periapsis
- 126.6594321390785
- absolute magnitude
- 11.78
- Commons category
- 1632 Sieböhme
- albedo
- 0.06
- rotation period
- 56.65
- time of periapsis
- 2460857.001944388
- epoch
- November 21, 2025
via Wikidata · CC0
~3 min read
Encyclopedic overview
1632 Sieböhme, provisional designation 1941 DF, is an asteroid and relatively slow rotator from the middle region of the asteroid belt, approximately 27 kilometers in diameter. It was discovered on 26 February 1941, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany. It was later named after ARI-astronomer Siegfried Böhme.
Orbital characteristics
Excerpted from Wikipedia’s “1632 Sieböhme” article, available under the CC BY-SA 4.0 licence.