Q140548

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

Y. Väisälä

Discovery site

Turku Observatory

Discovery date

18 September 1939

Named after

Pielinen (lake)

Alternative designations

1939 SE · 1929 RZ, 1931 ED · 1934 CW, 1939 TP · 1939 UK, 1952 RW · A903 SF, A916 RA

Minor planet category

main-belt · Flora

Observation arc

113.68 yr (41,521 days)

Aphelion

2.6342 AU

Perihelion

1.7736 AU

Semi major axis

2.2039 AU

Orbital period sidereal

3.27 yr (1,195 days)

Mean anomaly

295.85 °

Mean motion

0° 18 4.32 / day

Inclination

1.5344°

Longitude of ascending node

195.69°

Argument of perihelion

170.76°

Dimensions

7.38 ± 1.62 km , 7.82 km (calculated) , 7.934 ± 0.037 km , 7.975 ± 0.109 km

Synodic rotation period

66.1 ± 0.1 h , 66.22 h , 66.34 ± 0.02 h , 67.43 ± 0.06 h

via Wikipedia infobox