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
- 20 January 1939
- Named after
- Kollaa River , ( river in Karelia )
- Alternative designations
- 1939 BS · 1939 CH, 1943 GG · 1968 BH, 1976 JF 3
- Minor planet category
- main-belt · Vestian
- Observation arc
- 48.64 yr (17,766 days)
- Aphelion
- 2.5396 AU
- Perihelion
- 2.1862 AU
- Semi major axis
- 2.3629 AU
- Orbital period sidereal
- 3.63 yr (1,327 days)
- Mean anomaly
- 226.60 °
- Mean motion
- 0° 16 17.04 / day
- Inclination
- 7.7797°
- Longitude of ascending node
- 65.429°
- Argument of perihelion
- 71.220°
- Dimensions
- 6.06 km (calculated) , 6.71 ± 0.34 km , 7.772 ± 0.147 km
- Synodic rotation period
- 2.980 ± 0.005 h , 2.9887 ± 0.0004 h
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Kollaa
- Followed by
- 1930 Lucifer
- Follows
- Q146073
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 7.772
- Orbital period
- 1326.834666411957
Show 18 more facts
- discoverer or inventor
- Yrjö Väisälä
- site of astronomical discovery
- Iso-Heikkilä Observatory
- provisional designation
- 1976 JF3
- time of discovery or invention
- 1939-01-20
- orbital eccentricity
- 0.07609361852816458
- orbital inclination
- 7.772592391855112
- periapsis
- 2.183267192747802
- apoapsis
- 2.542898220829563
- semi-major axis of an orbit
- 2.363082706788683
- mean anomaly
- 320.1384105480362
- longitude of ascending node
- 65.34465857561305
- argument of periapsis
- 71.84970106996128
- absolute magnitude
- 12.93
- albedo
- 0.393
- rotation period
- 2.9887
- asteroid spectral type
- V-type asteroid
- time of periapsis
- 2461147.4159409534
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~3 min read
Encyclopedic overview
1929 Kollaa, provisional designation 1939 BS, is a stony Vestian asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland, on 20 January 1939. The asteroid was named after the Kollaa River in what is now Russia.
Orbit and classification
Excerpted from Wikipedia’s “Q146093” article, available under the CC BY-SA 4.0 licence.