Q141586

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

Ernest Johnson

Discovery site

Johannesburg Obs.

Discovery date

9 August 1948

Named after

Vivian Hirst, (daughter of an astronomer)

Alternative designations

1948 PL · 1951 EG 2 , 1954 SA · 1955 YC, 1960 WP · 1965 QB, 1965 UW · 1973 GG

Minor planet category

main-belt · Themis

Observation arc

68.64 yr (25,070 days)

Aphelion

3.6317 AU

Perihelion

2.6542 AU

Semi major axis

3.1429 AU

Orbital period sidereal

5.57 yr (2,035 days)

Mean anomaly

72.044 °

Mean motion

0° 10 36.84 / day

Inclination

2.4903°

Longitude of ascending node

115.62°

Argument of perihelion

316.97°

Dimensions

24.77 ± 6.52 km , 25.82 km (calculated) , 27.851 ± 0.351 km , 29.98 ± 1.74 km

Synodic rotation period

20.5209 ± 0.0007 h , 20.5235 h

via Wikipedia infobox

Wikidata facts

Diameter

27.851

Orbital period

2035.667897727657

Image

001623-asteroid shape model (1623) Vivian.png

via Wikidata · CC0