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
- 11 October 1936
- Named after
- August Kopff (astronomer)
- Alternative designations
- 1936 UC · 1926 TH, 1935 FG · 1946 SA, 1952 HV 2
- Minor planet category
- main-belt · Flora
- Observation arc
- 90.37 yr (33,006 days)
- Aphelion
- 2.7129 AU
- Perihelion
- 1.7572 AU
- Semi major axis
- 2.2350 AU
- Orbital period sidereal
- 3.34 yr (1,220 days)
- Mean anomaly
- 107.17 °
- Inclination
- 7.4943°
- Longitude of ascending node
- 16.826°
- Argument of perihelion
- 315.11°
- Dimensions
- 8.636 ± 0.395 km , 9.58 ± 0.21 km , 9.66 ± 1.2 km , 9.71 km (derived)
- Synodic rotation period
- 6.683 ± 0.001 h
- Geometric albedo
- 0.2497 ± 0.074 , 0.259 ± 0.012 , 0.2710 (derived) , 0.342 ± 0.061
via Wikipedia infobox
~3 min read
Encyclopedic overview
1631 Kopff (provisional designation 1936 UC) is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 11 October 1936, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland. It was later named after German astronomer August Kopff.
Classification and orbit
Excerpted from Wikipedia’s “Q141701” article, available under the CC BY-SA 4.0 licence.