536 Merapi

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

George Henry Peters

Discovery site

Washington, D.C.

Discovery date

11 May 1904

Pronunciation

/ m ə ˈ r ɑː p i /

Named after

Mount Mĕrapi , West Sumatera

Alternative designations

1904 OF

Adjectives

Merapian

Observation arc

111.94 yr (40885 d)

Aphelion

3.7977 AU (568.13 Gm )

Perihelion

3.1992 AU (478.59 Gm)

Semi major axis

3.4984 AU (523.35 Gm)

Orbital period sidereal

6.54 yr (2390.1 d )

Mean anomaly

302.40 °

Mean motion

0° 9 2.232 / day

Inclination

19.425°

Longitude of ascending node

59.239°

Argument of perihelion

295.862°

Mean radius

75.71 ± 4.5 km , 77.585 ± 1.765 km

via Wikipedia infobox

Wikidata facts

Diameter

147.066

Orbital period

2398.537877415349

via Wikidata · CC0