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
- C. J. van Houten , I. van Houten G. , T. Gehrels
- Discovery site
- Palomar Obs.
- Discovery date
- 24 September 1960
- Pronunciation
- / ə ˈ s aɪ r ɪ s /
- Named after
- Osiris (Egyptian mythology)
- Alternative designations
- 4011 P-L · 1964 TO 2 , 1966 FR · 1974 KN, 1974 KP · 1974 LE
- Minor planet category
- main-belt · ( inner ) , Sulamitis
- Observation arc
- 62.70 yr (22,900 days)
- Aphelion
- 2.5900 AU
- Perihelion
- 2.2813 AU
- Semi major axis
- 2.4356 AU
- Orbital period sidereal
- 3.80 yr (1,388 days)
- Mean anomaly
- 269.38 °
- Mean motion
- 0° 15 33.48 / day
- Inclination
- 4.9580°
- Longitude of ascending node
- 353.07°
- Argument of perihelion
- 106.04°
- Dimensions
- 13.1 km, 13.461 ± 0.206
via Wikipedia infobox
~3 min read
Encyclopedic overview
1923 Osiris, provisional designation 4011 P-L, is a dark asteroid from the inner regions of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 24 September 1960, by Ingrid and Cornelis Johannes van Houten at Leiden, on photographic plates taken by Tom Gehrels at Palomar Observatory in the United States. It was named after the Egyptian god Osiris.
Orbit and classification
Excerpted from Wikipedia’s “Q146020” article, available under the CC BY-SA 4.0 licence.