950 Ahrensa

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

1 April 1921

Named after

Ahrens family, (friends of discoverer)

Alternative designations

1921 JP · 1955 SU 2 , 1974 VG 3 · A904 RF

Minor planet category

main-belt · Phocaea

Observation arc

111.60 yr (40761 days)

Aphelion

2.7477 AU (411.05 Gm )

Perihelion

1.9958 AU (298.57 Gm)

Semi major axis

2.3717 AU (354.80 Gm)

Orbital period sidereal

3.65 yr (1334.1 d )

Mean anomaly

53.005 °

Mean motion

0° 16 11.424 / day

Inclination

23.477°

Longitude of ascending node

181.81°

Argument of perihelion

348.19°

Mean diameter

15.03 ± 1.8 ( IRAS :15) km , 16.21 ± 0.53 km , 14.299 ± 0.070 km , 16.66 ± 0.41 km , 15.34 km (derived)

Synodic rotation period

202 ± 1 h , 202 h (8.4 d )

via Wikipedia infobox