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
- W. Baade
- Discovery site
- Bergedorf Obs.
- Discovery date
- 10 March 1920
- Pronunciation
- / w ɛ s t ˈ f eɪ l i ə /
- Named after
- Westphalia , (German region)
- Alternative designations
- A920 EE · 1920 GS, A916 DD · 1916 DD
- Minor planet category
- main-belt · ( inner ) , background · slow
- Observation arc
- 99.58 yr (36,370 d)
- Aphelion
- 2.7792 AU
- Perihelion
- 2.0828 AU
- Semi major axis
- 2.4310 AU
- Orbital period sidereal
- 3.79 yr (1,384 d)
- Mean anomaly
- 32.395 °
- Mean motion
- 0° 15 36 / day
- Inclination
- 15.336°
- Longitude of ascending node
- 340.94°
- Argument of perihelion
- 329.98°
- Mean diameter
- 34.922 ± 0.153 km 36.48 ± 1.4 km 39.51 ± 1.47 km
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Westphalia
- Followed by
- 931 Whittemora
- Follows
- 929 Algunde
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 34.922
- Orbital period
- 1384.826227030479
Show 18 more facts
- discoverer or inventor
- Walter Baade
- site of astronomical discovery
- Hamburg-Bergedorf Observatory
- provisional designation
- A920 EE
- time of discovery or invention
- 1920-03-10
- orbital inclination
- 15.34351284592235
- asteroid spectral type
- C-type asteroid
- albedo
- 0.032
- rotation period
- 100.66
- absolute magnitude
- 11.35
- orbital eccentricity
- 0.1436841309896529
- semi-major axis of an orbit
- 2.431445663983598
- periapsis
- 2.082085506705555
- apoapsis
- 2.78080582126164
- longitude of ascending node
- 340.8068047721088
- argument of periapsis
- 330.7358391289774
- mean anomaly
- 191.5180526367602
- time of periapsis
- 2461648.6061652494
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~4 min read
Encyclopedic overview
930 Westphalia (prov. designation: A920 EE or 1920 GS) is a very dark background asteroid and a slow rotator from the inner regions of the asteroid belt, that measures approximately 36 kilometers (22 miles) in diameter. It was discovered on 10 March 1920, by German astronomer Walter Baade at the Bergedorf Observatory in Hamburg. The carbonaceous C-type asteroid (Ch) has an exceptionally long rotation period of 100.7 hours and is likely spherical in shape. It was named after Westphalia, a region in northwestern Germany.
Orbit and classification
Excerpted from Wikipedia’s “930 Westphalia” article, available under the CC BY-SA 4.0 licence.