1025 Riema

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

12 August 1923

Named after

Johannes Riem, (German astronomer)

Alternative designations

1923 NX · A923 QA

Minor planet category

main-belt · ( inner ) · Hungaria

Observation arc

93.81 yr (34,264 days)

Aphelion

2.0572 AU

Perihelion

1.9009 AU

Semi major axis

1.9790 AU

Orbital period sidereal

2.78 yr (1,017 days)

Mean anomaly

102.31 °

Mean motion

0° 21 14.4 / day

Inclination

26.863°

Longitude of ascending node

163.39°

Argument of perihelion

349.06°

Dimensions

4.605 ± 0.171 km , 5.48 km (derived)

Synodic rotation period

3.566 ± 0.005 h , 3.578 ± 0.002 h , 3.580 ± 0.005 h , 3.581 ± 0.002 h , 3.581 ± 0.001 h , 3.588 ± 0.002 h , 6.557 ± 0.001 h

via Wikipedia infobox