726 Joëlla

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

Joel Hastings Metcalf

Discovery site

Winchester, Massachusetts

Discovery date

22 November 1911

Pronunciation

/ dʒ oʊ ˈ ɛ l ə /

Alternative designations

1911 NM

Observation arc

84.76 yr (30958 d)

Aphelion

3.2978 AU (493.34 Gm )

Perihelion

1.8387 AU (275.07 Gm)

Semi major axis

2.5683 AU (384.21 Gm)

Orbital period sidereal

4.12 yr (1503.4 d )

Mean anomaly

203.587 °

Mean motion

0° 14 22.092 / day

Inclination

15.414°

Longitude of ascending node

242.040°

Argument of perihelion

112.979°

Mean radius

22.01 ± 1.75 km

Synodic rotation period

13.04 h (0.543 d )

Geometric albedo

0.0539 ± 0.010

via Wikipedia infobox