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
- C. H. F. Peters
- Discovery date
- 14 October 1877
- Pronunciation
- / iː ˈ d uː n ə /
- Named after
- Iðunn
- Alternative designations
- A877 TB; 1945 RQ
- Minor planet category
- Main belt
- Observation arc
- 138.50 yr (50587 d)
- Aphelion
- 3.7235 AU (557.03 Gm )
- Perihelion
- 2.6526 AU (396.82 Gm)
- Semi major axis
- 3.1880 AU (476.92 Gm)
- Orbital period sidereal
- 5.69 yr (2079.1 d )
- Mean anomaly
- 165.15 °
- Mean motion
- 0° 10 23.34 / day
- Inclination
- 22.660°
- Longitude of ascending node
- 200.50°
- Argument of perihelion
- 188.17°
- Earth moid
- 1.65682 AU (247.857 Gm)
- Jupiter moid
- 1.73015 AU (258.827 Gm)
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Iðunn
- Followed by
- Q214387
- Follows
- 175 Andromache
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 106.976
- Orbital period
- 2071.515748900403
Show 20 more facts
- discoverer or inventor
- Christian Heinrich Friedrich Peters
- site of astronomical discovery
- Litchfield Observatory
- provisional designation
- A877 TB
- time of discovery or invention
- 1877-10-14
- asteroid spectral type
- C-type asteroid
- orbital inclination
- 22.67612768732267
- albedo
- 0.065
- Commons category
- 176 Iduna
- rotation period
- 11.2877
- described by source
- Brockhaus and Efron Encyclopedic Dictionary
- absolute magnitude
- 8.44
- orbital eccentricity
- 0.1722467569371105
- semi-major axis of an orbit
- 3.180239848699425
- periapsis
- 2.632453848478782
- apoapsis
- 3.728025848920068
- longitude of ascending node
- 200.4517539428184
- argument of periapsis
- 189.0264606639539
- mean anomaly
- 34.81372697819832
- time of periapsis
- 2460800.1744896853
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~2 min read
Encyclopedic overview
176 Iduna is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York. It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun (Iðunn, Iduna) is also a Norse goddess. A G-type asteroid, it has a composition similar to that of the largest main-belt asteroid, 1 Ceres.
An occultation of a star by Iduna was observed from Mexico on January 17, 1998.
Excerpted from Wikipedia’s “176 Iduna” article, available under the CC BY-SA 4.0 licence.