Image by Cicero7 on Pixabay · Pixabay License
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
- 1 April 1921
- Named after
- Ahrens family, (friends of discoverer)
- Alternative designations
- 1921 JP · 1955 SU 2 , 1974 VG 3 · A904 RF
- Minor planet category
- main-belt · Phocaea
- Observation arc
- 111.60 yr (40761 days)
- Aphelion
- 2.7477 AU (411.05 Gm )
- Perihelion
- 1.9958 AU (298.57 Gm)
- Semi major axis
- 2.3717 AU (354.80 Gm)
- Orbital period sidereal
- 3.65 yr (1334.1 d )
- Mean anomaly
- 53.005 °
- Mean motion
- 0° 16 11.424 / day
- Inclination
- 23.477°
- Longitude of ascending node
- 181.81°
- Argument of perihelion
- 348.19°
- Mean diameter
- 15.03 ± 1.8 ( IRAS :15) km , 16.21 ± 0.53 km , 14.299 ± 0.070 km , 16.66 ± 0.41 km , 15.34 km (derived)
- Synodic rotation period
- 202 ± 1 h , 202 h (8.4 d )
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 951 Gaspra
- Follows
- Q158197
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 13.704
- Orbital period
- 1333.120410963914
- Image
- 000950-asteroid shape model (950) Ahrensa.png
Show 19 more facts
- discoverer or inventor
- Karl Wilhelm Reinmuth
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A921 GG
- time of discovery or invention
- 1921-04-01
- orbital inclination
- 23.50498047343601
- Commons category
- 950 Ahrensa
- albedo
- 0.231
- rotation period
- 202.0
- asteroid spectral type
- S-type asteroid
- absolute magnitude
- 11.34
- orbital eccentricity
- 0.1597910262912977
- semi-major axis of an orbit
- 2.37054006940838
- periapsis
- 1.991749038852971
- apoapsis
- 2.749331099963789
- longitude of ascending node
- 181.7158275473272
- argument of periapsis
- 348.5284335713324
- mean anomaly
- 250.2345029927587
- time of periapsis
- 2461406.9739568885
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~2 min read
Encyclopedic overview
950 Ahrensa, provisional designation 1921 JP, is a stony Phocaea asteroid and slow rotator from the inner regions of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 1 April 1921, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.
Description
Excerpted from Wikipedia’s “950 Ahrensa” article, available under the CC BY-SA 4.0 licence.