Q139640

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 Obs.

Discovery date

22 October 1938

Named after

Ounasjoki River, (in Finland)

Alternative designations

1938 UT · 1950 NZ, 1950 PB 1

Minor planet category

main-belt · ( middle )

Observation arc

77.90 yr (28,452 days)

Aphelion

3.1862 AU

Perihelion

1.9623 AU

Semi major axis

2.5743 AU

Orbital period sidereal

4.13 yr (1,509 days)

Mean anomaly

19.843 °

Mean motion

0° 14 18.96 / day

Inclination

13.651°

Longitude of ascending node

216.52°

Argument of perihelion

129.42°

Dimensions

17.62 km (derived) , 18.164 ± 0.109 , 20.032 km (dated)

Synodic rotation period

16 h (dated) , 139.1 ± 0.1 h , 139.1 ± 0.5 h

via Wikipedia infobox

Wikidata facts

Diameter

18.164

Orbital period

1509.561936835094

via Wikidata · CC0