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
- K. Reinmuth
- Discovery site
- Heidelberg
- Discovery date
- 4 August 1921
- Alternative designations
- 1905 UN · 1920 GC · 1921 PC · 1943 PE · 1952 BE 2
- Observation arc
- 109.65 yr (40051 days)
- Aphelion
- 3.6711 AU (549.19 Gm )
- Perihelion
- 2.5915 AU (387.68 Gm)
- Semi major axis
- 3.1313 AU (468.44 Gm)
- Orbital period sidereal
- 5.54 yr (2023.9 d )
- Mean anomaly
- 34.454 °
- Mean motion
- 0° 10 40.332 / day
- Inclination
- 1.1694°
- Longitude of ascending node
- 163.235°
- Argument of perihelion
- 151.503°
- Mean radius
- 26.03 ± 0.41 km
- Synodic rotation period
- 7.207 ± 0.002 h
- Geometric albedo
- 0.06 ( geometric )
- Spectral type
- FCX
via Wikipedia infobox
Wikidata facts
- Diameter
- 58.771
- Orbital period
- 2021.228254339472
Show 14 more facts
- provisional designation
- A921 PC
- time of discovery or invention
- 1921-08-04
- orbital inclination
- 1.172665121560057
- albedo
- 0.06
- rotation period
- 7.207
- absolute magnitude
- 10.16
- orbital eccentricity
- 0.1736661351165009
- semi-major axis of an orbit
- 3.128560965850656
- periapsis
- 2.585235874435025
- apoapsis
- 3.671886057266287
- longitude of ascending node
- 163.2202828447183
- argument of periapsis
- 150.2101146266638
- mean anomaly
- 281.1679786458018
- time of periapsis
- 2461443.1041914104
Sources (2)
via Wikidata · CC0
~1 min read
Article
954 Li is a main belt asteroid and member of the Themis family. It was discovered by Karl Wilhelm Reinmuth on 4 August 1921 and was named after his wife Lina Alstede Reinmuth, who also had 955 Alstede named after her. Classified as an FCX-type asteroid under the Tholen classification scheme, Li's spectrum may indicate aqueous alteration. The asteroid is estimated to be around 52 kilometres (32 mi) in size, and observations of its lightcurve—variations in its observed brightness—indicate that it rotates once every 7.2 hours.
Notes