File:000673-asteroid_shape_model_(673)_Edda.png · Wikimedia Commons · See Wikimedia Commons
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
- Joel Hastings Metcalf
- Discovery site
- Taunton, Massachusetts
- Discovery date
- 20 September 1908
- Pronunciation
- / ˈ ɛ d ə /
- Alternative designations
- 1908 EA
- Observation arc
- 107.57 yr (39290 d)
- Aphelion
- 2.8471 AU (425.92 Gm )
- Perihelion
- 2.7821 AU (416.20 Gm)
- Semi major axis
- 2.8146 AU (421.06 Gm)
- Orbital period sidereal
- 4.72 yr (1,724.7 d) 4.72 yr (1724.7 d )
- Mean anomaly
- 199.04 °
- Mean motion
- 0° 12 31.428 / day
- Inclination
- 2.8770°
- Longitude of ascending node
- 226.723°
- Argument of perihelion
- 236.303°
- Mean radius
- 18.765 ± 0.5 km
- Synodic rotation period
- 22.340 h (0.9308 d )
- Geometric albedo
- 0.1044 ± 0.006
via Wikipedia infobox
Wikidata facts
- Diameter
- 37.622
- Orbital period
- 1725.274528275302
- Image
- 000673-asteroid shape model (673) Edda.png
Show 15 more facts
- provisional designation
- A908 SG
- time of discovery or invention
- 1908-09-20
- orbital inclination
- 2.880746527445637
- Commons category
- 673 Edda
- albedo
- 0.092
- rotation period
- 22.34
- absolute magnitude
- 10.12
- orbital eccentricity
- 0.008937473022632108
- semi-major axis of an orbit
- 2.815182294415012
- periapsis
- 2.790021678604886
- apoapsis
- 2.840342910225137
- longitude of ascending node
- 226.3885396098876
- argument of periapsis
- 256.5976750801498
- mean anomaly
- 168.4640364432142
- time of periapsis
- 2460193.1480249837
Sources (2)
via Wikidata · CC0
~1 min read
Article
673 Edda is a minor planet orbiting the Sun. It was discovered 20 September 1908 by the American astronomer Joel Hastings Metcalf, and was named for the Norse Edda literary works. The name may also have been inspired by the asteroid's provisional designation 1908 EA. This asteroid is orbiting at a distance of 2.81 AU with a period of 4.72 yr and an eccentricity of 0.012. The orbit is close to a 5:2 mean motion resonance with Jupiter, which is located at 2.824 AU.
The long rotation period and low brightness amplitude of this asteroid make it more challenging for measurement of the rotation period. An extensive photometry campaign in 2015 provided a period of 22.340±0.004 h. The unusual light curve suggests that the asteroid shape is very asymmetric. It is a stony S-type asteroid with a mean diameter of 38+6 −2 km.