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
- E. Delporte
- Discovery site
- Uccle Obs.
- Discovery date
- 26 August 1938
- Named after
- Sigrid Strömgren , (wife of astronomer) , Bengt Strömgren
- Alternative designations
- 1938 QB · 1934 NB 1 , 1934 PW · 1957 UT, 1961 TM 1 · 1961 XL, 1977 UN · A908 WA, A916 YD
- Minor planet category
- main-belt · ( inner ) , Nysa
- Observation arc
- 108.52 yr (39,636 days)
- Aphelion
- 2.9175 AU
- Perihelion
- 1.9416 AU
- Semi major axis
- 2.4295 AU
- Orbital period sidereal
- 3.79 yr (1,383 days)
- Mean anomaly
- 318.09 °
- Mean motion
- 0° 15 37.08 / day
- Inclination
- 2.5772°
- Longitude of ascending node
- 330.58°
- Argument of perihelion
- 1.6890°
- Dimensions
- 22.111 ± 0.200 km , 22.93 ± 6.77 km , 23 ± 2 km , 23.76 ± 3.46 km , 24.03 ± 2.1 km , 24.92 ± 8.61 km , 25.10 ± 0.42 km , 27.8 ± 5.6 km , 28.905 ± 0.401 km
- Synodic rotation period
- 22.68 ± 0.02 h , 43.179 ± 0.005 h , 43.1795 ± 0.0001 h , 43.296 ± 0.048 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 28.905
- Orbital period
- 1383.315402599128
- Image
- 001493-asteroid shape model (1493) Sigrid.png
Show 14 more facts
- provisional designation
- A916 YD
- time of discovery or invention
- 1938-08-26
- orbital eccentricity
- 0.2008402135735808
- albedo
- 0.034
- orbital inclination
- 2.575936943466211
- periapsis
- 1.941700068773148
- apoapsis
- 2.917653721926944
- semi-major axis of an orbit
- 2.429676895350046
- mean anomaly
- 19.04932735796611
- longitude of ascending node
- 330.5360287509731
- argument of periapsis
- 1.529372101280992
- absolute magnitude
- 12.11
- rotation period
- 43.296
- time of periapsis
- 2460927.3021446015
Sources (2)
via Wikidata · CC0
~4 min read
Article
1493 Sigrid, provisional designation 1938 QB, is a dark Nysian asteroid from the inner regions of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 26 August 1938, by Belgian astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle. It was named after Sigrid Strömgren, wife of astronomer Bengt Strömgren.
Orbit and classification