Image by Toby_Parsons on Pixabay · Pixabay License
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
- K. Reinmuth
- Discovery site
- Heidelberg Obs.
- Discovery date
- 23 February 1920
- Named after
- Name picked from the almanac , Lahrer Hinkender Bote
- Alternative designations
- A920 DC · 1920 GP, 1959 EE 1
- Minor planet category
- main-belt · ( outer ) , background
- Observation arc
- 99.79 yr (36,447 d)
- Aphelion
- 3.5999 AU
- Perihelion
- 2.6698 AU
- Semi major axis
- 3.1349 AU
- Orbital period sidereal
- 5.55 yr (2,027 d)
- Mean anomaly
- 9.2453 °
- Mean motion
- 0° 10 39.36 / day
- Inclination
- 17.653°
- Longitude of ascending node
- 129.83°
- Argument of perihelion
- 21.894°
- Mean diameter
- 62.817 ± 0.293 km 64.04 ± 1.09 km 66.49 ± 1.7 km
- Synodic rotation period
- 14.13 ± 0.03 h
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- Q158061
- Follows
- Q158051
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 62.817
- Orbital period
- 2031.763794159691
- Image
- 000928-asteroid shape model (928) Hildrun.png
Show 18 more facts
- discoverer or inventor
- Karl Wilhelm Reinmuth
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A920 DC
- time of discovery or invention
- 1920-02-23
- orbital inclination
- 17.65304795464369
- albedo
- 0.053
- Commons category
- 928 Hildrun
- rotation period
- 14.13
- absolute magnitude
- 9.96
- orbital eccentricity
- 0.1435235468104383
- semi-major axis of an orbit
- 3.139423176346925
- periapsis
- 2.688842027138723
- apoapsis
- 3.590004325555128
- longitude of ascending node
- 129.5798016167255
- argument of periapsis
- 21.41534380847402
- mean anomaly
- 4.626189267961429
- time of periapsis
- 2460974.390767057
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~5 min read
Encyclopedic overview
928 Hildrun (prov. designation: A920 DC or 1920 GP), is a dark background asteroid, approximately 64 kilometers (40 miles) in diameter, located in the outer region of the asteroid belt. It was discovered on 23 February 1920, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The X-type asteroid has a rotation period of 14.1 hours. It was named "Hildrun", a common German female name unrelated to the discoverer's contemporaries, that was taken from the almanac Lahrer Hinkender Bote.
Orbit and classification
Excerpted from Wikipedia’s “928 Hildrun” article, available under the CC BY-SA 4.0 licence.