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
- Max Wolf
- Discovery site
- Heidelberg Observatory
- Discovery date
- 17 April 1915
- Alternative designations
- 1915 WW
- Observation arc
- 100.85 yr (36835 d)
- Aphelion
- 3.7899 AU (566.96 Gm )
- Perihelion
- 2.5947 AU (388.16 Gm)
- Semi major axis
- 3.1923 AU (477.56 Gm)
- Orbital period sidereal
- 5.70 yr (2083.3 d )
- Mean anomaly
- 132.402 °
- Mean motion
- 0° 10 22.08 / day
- Inclination
- 15.728°
- Longitude of ascending node
- 166.446°
- Argument of perihelion
- 132.362°
- Earth moid
- 1.60843 AU (240.618 Gm)
- Jupiter moid
- 1.7152 AU (256.59 Gm)
- Mean radius
- 33.47 ± 1.45 km
- Synodic rotation period
- 9.510 h (0.3963 d )
via Wikipedia infobox
Wikidata facts
- Diameter
- 73.095
- Orbital period
- 2087.553490563479
Show 14 more facts
- provisional designation
- A915 HD
- time of discovery or invention
- 1915-04-17
- orbital inclination
- 15.72462940604496
- albedo
- 0.039
- rotation period
- 9.51
- absolute magnitude
- 9.84
- orbital eccentricity
- 0.1854540050636921
- semi-major axis of an orbit
- 3.196633087425582
- periapsis
- 2.603804678643392
- apoapsis
- 3.789461496207772
- longitude of ascending node
- 166.3304897294129
- argument of periapsis
- 131.6208936833038
- mean anomaly
- 0.4207519186487025
- time of periapsis
- 2460998.060160732
Sources (2)
via Wikidata · CC0
~1 min read
Article
805 Hormuthia is a minor planet orbiting the Sun. This asteroid follows an elliptical orbit through the main asteroid belt that reaches perihelion just outside the Kirkwood gap at 2.5 AU. Its estimated diameter is 73 km, and it is one of the 500 largest asteroids. 805 Hormuthia was discovered by Max Wolf in 1915, at the University of Heidelberg. The planet is named after Hormuth Kopff, the wife of astronomer August Kopff.
References