655 Briseïs

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

Taunton, Massachusetts

Discovery date

4 November 1907

Pronunciation

/ b r aɪ ˈ s iː ɪ s /

Alternative designations

1907 BF

Observation arc

108.19 yr (39515 d)

Aphelion

3.2489 AU (486.03 Gm )

Perihelion

2.7297 AU (408.36 Gm)

Semi major axis

2.9893 AU (447.19 Gm)

Orbital period sidereal

5.17 yr (1887.8 d )

Mean anomaly

8.32168 °

Mean motion

0° 11 26.52 / day

Inclination

6.4972°

Longitude of ascending node

130.064°

Argument of perihelion

278.531°

Mean radius

15.395 ± 0.95 km

Synodic rotation period

160.66 h (6.694 d )

Geometric albedo

0.2693 ± 0.036

via Wikipedia infobox