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
- L. Kohoutek
- Discovery site
- Bergedorf Obs.
- Discovery date
- 26 October 1971
- Named after
- Jan Hus ( early Reformer )
- Alternative designations
- 1971 UY · 1931 TS 3 , 1935 NC · 1953 CG
- Minor planet category
- main-belt · ( outer ) , Koronis
- Observation arc
- 86.72 yr (31,673 d)
- Aphelion
- 2.9646 AU
- Perihelion
- 2.8731 AU
- Semi major axis
- 2.9188 AU
- Orbital period sidereal
- 4.99 yr (1,821 d)
- Mean anomaly
- 174.31 °
- Mean motion
- 0° 11 51.36 / day
- Inclination
- 2.4077°
- Longitude of ascending node
- 40.525°
- Argument of perihelion
- 14.250°
- Mean diameter
- 12.446 ± 0.193 km , 12.592 ± 0.123 km
- Synodic rotation period
- 4.7483 ± 0.0008 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 12.446
- Orbital period
- 1820.020700981653
- Image
- 001840-asteroid shape model (1840) Hus.png
Show 15 more facts
- provisional designation
- 1971 UY
- time of discovery or invention
- 1971-10-26
- orbital inclination
- 2.403185053973103
- orbital eccentricity
- 0.01479999632409239
- periapsis
- 2.874151602012043
- apoapsis
- 2.960504490737073
- semi-major axis of an orbit
- 2.917328046374558
- mean anomaly
- 273.6791316500888
- longitude of ascending node
- 40.328022565782
- argument of periapsis
- 29.47214829739766
- absolute magnitude
- 11.73
- albedo
- 0.261
- Commons category
- 1840 Hus
- rotation period
- 4.75
- time of periapsis
- 2461436.904909232
Sources (2)
via Wikidata · CC0
~4 min read
Article
1840 Hus (prov. designation: 1971 UY) is a stony Koronis asteroid from the outer regions of the asteroid belt, approximately 12.5 kilometers (7.8 miles) in diameter. It was discovered on 26 October 1971, by Czech astronomer Luboš Kohoutek at the Bergedorf Observatory in Hamburg, Germany. The S-type asteroid has a rotation period of 4.8 hours and is likely elongated in shape. It was later named after 15th-century theologian Jan Hus.
Orbit and classification