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
- Johann Palisa
- Discovery date
- 31 March 1886
- Pronunciation
- / ɒ ˈ p eɪ v i ə /
- Named after
- Opava
- Alternative designations
- A886 FB, 1904 EC, 1924 TA, 1938 VC, 1938 XC, 1945 GD, 1951 SG
- Minor planet category
- Main belt
- Observation arc
- 129.86 yr (47,431 d)
- Aphelion
- 2.959 AU (442.6 Gm )
- Perihelion
- 2.533 AU (379.0 Gm)
- Semi major axis
- 2.746 AU (410.8 Gm)
- Orbital period sidereal
- 4.551 yr (1,662.1 d)
- Average orbital speed
- 17.98 km/s
- Mean anomaly
- 261.139 °
- Mean motion
- 0° 12 59.735 / day
- Inclination
- 9.47209°
- Longitude of ascending node
- 13.6708°
- Argument of perihelion
- 156.011°
- Dimensions
- 57.40 ± 1.5 km
via Wikipedia infobox
Wikidata facts
- Diameter
- 56.939
- Orbital period
- 1662.605560006474
Show 14 more facts
- provisional designation
- A886 FB
- time of discovery or invention
- 1886-03-31
- orbital inclination
- 9.460609647149822
- albedo
- 0.038
- rotation period
- 19.499
- absolute magnitude
- 10.53
- orbital eccentricity
- 0.07896220470549731
- semi-major axis of an orbit
- 2.74659021029433
- periapsis
- 2.529713391866954
- apoapsis
- 2.963467028721705
- longitude of ascending node
- 13.554799566389
- argument of periapsis
- 153.988397523522
- mean anomaly
- 279.7327891734483
- time of periapsis
- 2461371.201975018
Sources (2)
via Wikidata · CC0
~1 min read
Article
255 Oppavia is a sizeable Main belt asteroid. It was discovered by Austrian astronomer Johann Palisa on 31 March 1886 in Vienna and was named after Opava, a town in the Czech Republic, then part of Austria-Hungary, where Palisa was born. It is orbiting the Sun at a distance of 2.75 AU with an orbital eccentricity (ovalness) of 0.077 and a period of 4.55 yr. The orbital plane is inclined by an angle of 9.47° to the plane of the ecliptic.
Photometric observations made during 2013 indicate a synodic rotation period of 19.499±0.001 h with an amplitude of 0.16±0.02 in magnitude. The unusual light curve shows three uneven minima and maxima per cycle. In 1995, 255 Oppavia was suggested as a peripheral member of the now defunct Ceres asteroid family, but was found to be an unrelated interloper on the basis of its non-matching spectral type. It classified as a dark X-type asteroid in the Tholen taxonomy.