1691 Oort

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 , I. Groeneveld

Discovery site

Heidelberg Obs.

Discovery date

9 September 1956

Named after

Jan Oort (astronomer)

Alternative designations

1956 RB · 1945 TD, 1947 DA · 1950 PZ, 1950 RU · 1951 XW, 1955 MW · 1956 SD, 1964 DA · A917 TD

Minor planet category

main-belt · Themis

Observation arc

71.42 yr (26,086 days)

Aphelion

3.7153 AU

Perihelion

2.6084 AU

Semi major axis

3.1618 AU

Orbital period sidereal

5.62 yr (2,054 days)

Mean anomaly

240.25 °

Inclination

1.0860°

Longitude of ascending node

174.55°

Argument of perihelion

232.69°

Dimensions

27.13 km (calculated) , 33.163 ± 0.534 km , 33.644 ± 0.267 , 37.37 ± 0.74 km

Synodic rotation period

10.2684 ± 0.0005 h , 10.2705 ± 0.0004 h

Geometric albedo

0.053 ± 0.002 , 0.065 ± 0.011 , 0.0672 ± 0.0150 , 0.10 (assumed)

via Wikipedia infobox