729 Watsonia

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

Winchester, Massachusetts

Discovery date

9 February 1912

Pronunciation

/ w ɒ t ˈ s oʊ n i ə /

Alternative designations

1912 OD

Observation arc

98.79 yr (36082 d)

Aphelion

3.0270 AU (452.83 Gm )

Perihelion

2.4917 AU (372.75 Gm)

Semi major axis

2.7594 AU (412.80 Gm)

Orbital period sidereal

4.58 yr (1674.2 d )

Mean anomaly

223.02 °

Mean motion

0° 12 54.108 / day

Inclination

18.042°

Longitude of ascending node

124.388°

Argument of perihelion

88.376°

Mean radius

24.575 ± 0.75 km

Synodic rotation period

25.230 h (1.0513 d )

Geometric albedo

0.1381 ± 0.009

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Followed by

730 Athanasia

Follows

728 Leonisis

Parent body

Sun

Minor-planet group

asteroid belt

Diameter

50.025

Orbital period

1675.520628116313

via Wikidata · CC0