189 Phthia

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

C. H. F. Peters

Discovery site

Clinton, New York

Discovery date

9 September 1878

Pronunciation

/ ˈ θ aɪ . ə /

Alternative designations

A878 RA

Minor planet category

main-belt

Observation arc

136.18 yr (49739 d)

Aphelion

2.5415 AU (380.20 Gm )

Perihelion

2.3597 AU (353.01 Gm)

Semi major axis

2.4506 AU (366.60 Gm)

Orbital period sidereal

3.84 yr (1401.2 d )

Mean anomaly

336.98 °

Mean motion

0° 15 24.912 / day

Inclination

5.1774°

Longitude of ascending node

203.42°

Argument of perihelion

168.03°

Dimensions

37.66 ± 2.0 km , 40.91 ± 1.36 km

Mass

(3.84 ± 0.81) × 10 kg

via Wikipedia infobox

Wikidata facts

Diameter

38.49

Orbital period

1401.112731877681

via Wikidata · CC0