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
- August Kopff
- Discovery site
- Heidelberg
- Discovery date
- 15 August 1909
- Alternative designations
- 1909 HF
- Minor planet category
- main-belt · ( middle ) , Gersuind
- Observation arc
- 106.67 yr (38960 d)
- Aphelion
- 3.2844 AU (491.34 Gm )
- Perihelion
- 1.8987 AU (284.04 Gm)
- Semi major axis
- 2.5915 AU (387.68 Gm)
- Orbital period sidereal
- 4.17 yr (1523.8 d )
- Mean anomaly
- 236.17 °
- Mean motion
- 0° 14 10.5 / day
- Inclination
- 15.672°
- Longitude of ascending node
- 243.103°
- Argument of perihelion
- 88.883°
- Mean radius
- 20.565 ± 2.25 km
- Synodic rotation period
- 6.3127 h (0.26303 d )
- Geometric albedo
- 0.1416 ± 0.037
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 687 Tinette
- Follows
- 685 Hermia
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 55.258
- Orbital period
- 1522.260601599296
Show 18 more facts
- discoverer or inventor
- August Kopff
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- 1909 HF
- time of discovery or invention
- 1909-08-15
- albedo
- 0.078
- rotation period
- 6.3127
- asteroid spectral type
- S-type asteroid
- absolute magnitude
- 9.63
- orbital eccentricity
- 0.2677108263860036
- semi-major axis of an orbit
- 2.589765177558188
- periapsis
- 1.89645700172839
- apoapsis
- 3.283073353387986
- orbital inclination
- 15.6892767308594
- longitude of ascending node
- 243.0117828226739
- argument of periapsis
- 88.96966693371255
- mean anomaly
- 320.4201294300898
- time of periapsis
- 2461167.8635488474
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
686 Gersuind is a minor planet orbiting the Sun that was discovered by German astronomer August Kopff on 15 August 1909 from Heidelberg. It was named after a character in Gerhart Hauptmann's play Gersuind.
This object is the namesake of a family of 40–207 asteroids that share similar spectral properties and orbital elements; hence they may have arisen from the same collisional event. All members have a relatively high orbital inclination.
Excerpted from Wikipedia’s “686 Gersuind” article, available under the CC BY-SA 4.0 licence.