1520 Imatra

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

Y. Väisälä

Discovery site

Turku Obs.

Discovery date

22 October 1938

Named after

Imatra (Finnish town)

Alternative designations

1938 UY · 1938 YH

Minor planet category

main-belt · ( outer ) , Ursula

Observation arc

78.53 yr (28,682 days)

Aphelion

3.4132 AU

Perihelion

2.8113 AU

Semi major axis

3.1123 AU

Orbital period sidereal

5.49 yr (2,005 days)

Mean anomaly

179.71 °

Mean motion

0° 10 46.2 / day

Inclination

15.241°

Longitude of ascending node

253.40°

Argument of perihelion

116.83°

Dimensions

53.41 km (derived) , 53.42 ± 19.70 km , 53.435 ± 0.370 km , 53.61 ± 1.4 km , 53.79 ± 14.73 km , 55.55 ± 0.60 km , 56.094 ± 1.824 km , 58.63 ± 0.70 km

Synodic rotation period

5.23 h (dated) , 18.609 ± 0.004 h , 18.635 ± 0.004 h

via Wikipedia infobox