Q11541

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

Discovery site

Heidelberg Obs.

Discovery date

31 October 1923

Pronunciation

German: [ ˈziːʁeːnə ]

Named after

Siren (Σειρήν - Sīrēn) (Greek mythology)

Alternative designations

1923 PE

Minor planet category

Mars-crosser

Observation arc

92.69 yr (33,854 days)

Aphelion

3.8207 AU

Perihelion

1.4259 AU

Semi major axis

2.6233 AU

Orbital period sidereal

4.25 yr (1,552 days)

Mean anomaly

11.512 °

Mean motion

0° 13 55.2 / day

Inclination

15.775°

Longitude of ascending node

229.46°

Argument of perihelion

186.35°

Earth moid

0.4384 AU · 170.8 LD

via Wikipedia infobox

Wikidata facts

Orbital period

1556.226181806039

via Wikidata · CC0