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
- J. Palisa
- Discovery site
- Vienna Obs.
- Discovery date
- 18 October 1911
- Pronunciation
- German: [ ˈfʁiːdaː ]
- Named after
- Frieda Hillebrand, daughter and grand-daughter of: , Karl Hillebrand [ de ] (1861–1939) , Edmund Weiss (1837–1917)
- Alternative designations
- A911 UN · 1926 GR, 1946 SH · 1911 NA
- Minor planet category
- main-belt · ( inner ) background
- Observation arc
- 109.52 yr (40,002 d)
- Aphelion
- 2.4858 AU
- Perihelion
- 1.8575 AU
- Semi major axis
- 2.1717 AU
- Orbital period sidereal
- 3.20 yr (1,169 d)
- Mean anomaly
- 47.845 °
- Mean motion
- 0° 18 28.8 / day
- Inclination
- 5.6371°
- Longitude of ascending node
- 45.668°
- Argument of perihelion
- 257.23°
- Mean diameter
- 8.257 ± 0.073 km 11.43 ± 0.23 km
via Wikipedia infobox
Wikidata facts
- Diameter
- 8.257
- Orbital period
- 1168.928611116676
Show 15 more facts
- provisional designation
- A911 UN
- time of discovery or invention
- 1911-10-18
- orbital inclination
- 5.635164702890573
- Commons category
- 722 Frieda
- albedo
- 0.252
- rotation period
- 131.1
- absolute magnitude
- 12.48
- orbital eccentricity
- 0.1455247034926838
- semi-major axis of an orbit
- 2.171666046100568
- periapsis
- 1.855634988656653
- apoapsis
- 2.487697103544482
- longitude of ascending node
- 45.64028515809112
- argument of periapsis
- 257.4153453414033
- mean anomaly
- 303.454773760897
- time of periapsis
- 2461184.103702147
Sources (2)
via Wikidata · CC0
~4 min read
Article
722 Frieda (prov. designation: A911 UN or 1911 NA) is a bright background asteroid and slow rotator from the inner regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 18 October 1911. The stony S-type asteroid has a notably long rotation period of 131.1 hours and measures approximately 9 kilometers (6 miles) in diameter. It was named after Frieda Hillebrand, daughter of Austrian astronomer Karl Hillebrand [de] (1861–1939), and grand-daughter of Edmund Weiss (1837–1917) who had been the director of the discovering observatory.
Orbit and classification