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
- Y. Väisälä
- Discovery site
- Turku Obs.
- Discovery date
- 6 February 1938
- Named after
- Ilmari Bonsdorff , (Finnish astronomer)
- Alternative designations
- 1938 CC · 1959 WD
- Minor planet category
- main-belt · ( outer ) , background
- Observation arc
- 63.72 yr (23,274 days)
- Aphelion
- 4.0797 AU
- Perihelion
- 2.3192 AU
- Semi major axis
- 3.1994 AU
- Orbital period sidereal
- 5.72 yr (2,090 days)
- Mean anomaly
- 69.903 °
- Mean motion
- 0° 10 19.92 / day
- Inclination
- 15.713°
- Longitude of ascending node
- 320.65°
- Argument of perihelion
- 103.38°
- Dimensions
- 25.85 ± 0.39 km , 28.10 ± 1.3 km , 29.13 ± 8.63 km , 35.87 ± 0.66 km
- Synodic rotation period
- 7.5 h , 7.8 ± 0.1 h
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 1478 Vihuri
- Follows
- 1476 Cox
- Parent body
- Sun
- Diameter
- 25.851
- Orbital period
- 2100.605949179814
Show 18 more facts
- discoverer or inventor
- Yrjö Väisälä
- site of astronomical discovery
- Iso-Heikkilä Observatory
- provisional designation
- 1959 WD
- time of discovery or invention
- 1938-02-06
- orbital eccentricity
- 0.2658617273701894
- orbital inclination
- 15.80878283723229
- periapsis
- 2.356542672725413
- apoapsis
- 4.063345134741343
- semi-major axis of an orbit
- 3.209943903733378
- mean anomaly
- 222.5418345323631
- longitude of ascending node
- 319.8054872599029
- argument of periapsis
- 105.4131908648887
- absolute magnitude
- 11.6
- albedo
- 0.032
- rotation period
- 7.8
- asteroid spectral type
- X-type asteroid
- time of periapsis
- 2461802.5706670685
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~3 min read
Encyclopedic overview
1477 Bonsdorffia, provisional designation 1938 CC, is a background asteroid from the outer regions of the asteroid belt, approximately 29 kilometers in diameter. It was discovered on 6 February 1938, by astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory in Turku, Finland. The asteroid was named after Finnish astronomer Ilmari Bonsdorff, who founded the Finnish Geodetic Institute.
Orbit and classification
Excerpted from Wikipedia’s “1477 Bonsdorffia” article, available under the CC BY-SA 4.0 licence.