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
- M. F. Wolf
- Discovery site
- Heidelberg Obs.
- Discovery date
- 13 March 1931
- Named after
- Irmela Ruska, (wife of Ernst Ruska )
- Alternative designations
- 1931 EC · 1940 GC, 1962 JD · 1988 CK 6
- Minor planet category
- main-belt · ( middle )
- Observation arc
- 85.83 yr (31,351 days)
- Aphelion
- 3.1700 AU
- Perihelion
- 2.1916 AU
- Semi major axis
- 2.6808 AU
- Orbital period sidereal
- 4.39 yr (1,603 days)
- Mean anomaly
- 209.87 °
- Mean motion
- 0° 13 28.56 / day
- Inclination
- 6.9511°
- Longitude of ascending node
- 170.11°
- Argument of perihelion
- 357.21°
- Dimensions
- 17.00 ± 3.43 km , 17.50 ± 4.91 km , 17.90 ± 0.57 km , 19.05 km (derived) , 19.09 ± 0.8 km ( IRAS :15) , 19.663 ± 0.049 km , 20.683 ± 0.181 km
- Synodic rotation period
- 11.989 ± 0.001 h , 19.17 h
via Wikipedia infobox
Wikidata facts
- Diameter
- 19.663
- Orbital period
- 1599.716954661841
Show 16 more facts
- provisional designation
- 1988 CK6
- time of discovery or invention
- 1931-03-13
- orbital eccentricity
- 0.1864404495476378
- albedo
- 0.07
- orbital inclination
- 6.968354883365761
- periapsis
- 2.177805857497411
- apoapsis
- 3.175965372368895
- semi-major axis of an orbit
- 2.676885614933153
- mean anomaly
- 208.8829639536593
- longitude of ascending node
- 169.9272110561102
- argument of periapsis
- 357.4942337608533
- absolute magnitude
- 12.06
- title
- (1178) Irmela
- page(s)
- 99-99
- rotation period
- 11.992
- time of periapsis
- 2461672.0124575044
Sources (2)
via Wikidata · CC0
~3 min read
Article
1178 Irmela, provisional designation 1931 EC, is a stony asteroid from the middle regions of the asteroid belt, approximately 19 kilometers in diameter.
It was discovered on 13 March 1931, by German astronomer Max Wolf at Heidelberg Observatory in southwest Germany. The asteroid was named after Irmela Ruska, wife of Ernst Ruska.