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
- 15 October 1938
- Named after
- Rovaniemi (Finnish city)
- Alternative designations
- 1938 UA · 1928 TL, 1951 SH
- Minor planet category
- main-belt · ( inner ) , Flora
- Observation arc
- 88.74 yr (32,412 days)
- Aphelion
- 2.5449 AU
- Perihelion
- 1.9053 AU
- Semi major axis
- 2.2251 AU
- Orbital period sidereal
- 3.32 yr (1,212 days)
- Mean anomaly
- 246.56 °
- Mean motion
- 0° 17 49.2 / day
- Inclination
- 6.7137°
- Longitude of ascending node
- 27.804°
- Argument of perihelion
- 37.101°
- Dimensions
- 7.46 ± 1.30 km , 7.76 ± 0.71 km , 8.480 ± 0.167 km , 8.98 km (calculated) , 9.019 ± 0.070 km
- Synodic rotation period
- 5.247 ± 0.001 h , 5.249 ± 0.002 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 8.48
- Orbital period
- 1212.768535124377
- Image
- 1518Rovaniemi (Lightcurve Inversion).png
Show 14 more facts
- provisional designation
- 1951 SH
- time of discovery or invention
- 1938-10-15
- orbital eccentricity
- 0.1431703574244106
- orbital inclination
- 6.711243545769777
- periapsis
- 1.906985885941038
- apoapsis
- 2.544274414084831
- semi-major axis of an orbit
- 2.225630150012935
- mean anomaly
- 56.98694449600579
- longitude of ascending node
- 27.68597770809046
- argument of periapsis
- 37.27324777377265
- absolute magnitude
- 12.44
- albedo
- 0.295
- rotation period
- 5.249
- time of periapsis
- 2460808.522296673
Sources (3)
via Wikidata · CC0
~4 min read
Article
1518 Rovaniemi (provisional designation 1938 UA) is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. Discovered by Yrjö Väisälä at the Turku Observatory in 1938, the asteroid was later named after the Finnish city of Rovaniemi.
Discovery