251 Sophia

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

J. Palisa

Discovery site

Vienna Obs.

Discovery date

4 October 1885

Pronunciation

German: [ zoːˈfiːaː ]

Named after

Sophia von Seeliger ( Hugo von Seeliger )

Alternative designations

A885 TA, 1907 UA, 1950 RH 1 , 1953 FN 1

Minor planet category

main-belt · ( outer ) background

Observation arc

134.29 yr (49,050 d)

Aphelion

3.4015 AU

Perihelion

2.8035 AU

Semi major axis

3.1025 AU

Orbital period sidereal

5.46 yr (1,996 d)

Mean anomaly

192.53 °

Mean motion

0° 10 49.44 / day

Inclination

10.511°

Longitude of ascending node

156.02°

Argument of perihelion

286.51°

Mean diameter

27.495 ± 0.197 km 28.42 ± 4.5 km 29.65 ± 0.42 km

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Followed by

252 Clementina

Follows

250 Bettina

Parent body

Sun

Minor-planet group

asteroid belt

Diameter

27.495

Orbital period

1992.716070666555

Image

000251-asteroid shape model (251) Sophia.png

via Wikidata · CC0