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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 Obs.
- Discovery date
- 22 August 1919
- Named after
- Name picked from the almanac , Lahrer Hinkender Bote
- Alternative designations
- A919 QD · 1919 FR, A907 CA · 1907 CA, 1943 PB
- Minor planet category
- main-belt · ( outer ) , Itha
- Observation arc
- 99.72 yr (36,421 d)
- Aphelion
- 3.4078 AU
- Perihelion
- 2.3197 AU
- Semi major axis
- 2.8637 AU
- Orbital period sidereal
- 4.85 yr (1,770 d)
- Mean anomaly
- 273.51 °
- Mean motion
- 0° 12 12.24 / day
- Inclination
- 12.070°
- Longitude of ascending node
- 330.46°
- Argument of perihelion
- 15.565°
- Mean diameter
- 20.44 ± 1.9 km 21.37 ± 0.84 km 21.561 ± 0.106 km
- Synodic rotation period
- 3.473 93 ± 0.000 06 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 21.561
- Orbital period
- 1772.437359618509
- Image
- 000918-asteroid shape model (918) Itha.png
Show 15 more facts
- provisional designation
- A919 QD
- time of discovery or invention
- 1919-08-22
- orbital inclination
- 12.0665651511047
- Commons category
- 918 Itha
- albedo
- 0.224
- rotation period
- 3.47393
- absolute magnitude
- 10.74
- orbital eccentricity
- 0.188225043670329
- semi-major axis of an orbit
- 2.866256014971666
- periapsis
- 2.326754851383281
- apoapsis
- 3.405757178560051
- longitude of ascending node
- 330.4175139803851
- argument of periapsis
- 15.24010949220944
- mean anomaly
- 320.2903654341065
- time of periapsis
- 2461196.0078884484
Sources (2)
via Wikidata · CC0
~5 min read
Article
918 Itha (prov. designation: A919 QD or 1919 FR) is a stony asteroid and the namesake as well as the principal body of the Itha family, located in the outer region of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 22 August 1919. The S-type asteroid has a notably short rotation period of only 3.5 hours and measures approximately 21 kilometers (13 miles) in diameter. It was named "Itha", a female name taken from the almanac Lahrer Hinkender Bote, unrelated to the discoverer's contemporaries.
Orbit and classification