87 Sylvia

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

Norman Robert Pogson

Discovery date

16 May 1866

Pronunciation

/ ˈ s ɪ l v i ə / SIL -vee-ə

Named after

Rhea Silvia

Alternative designations

A909 GA

Minor planet category

main belt · ( outside core ) , Sylvia · Cybele

Adjectives

Sylvian ( / ˈ s ɪ l v i ə n / SIL -vee-ən )

Aphelion

3.81 AU (560 million km)

Perihelion

3.15 AU (480 million km)

Semi major axis

3.48 AU (520 million km)

Orbital period sidereal

6.5 a (2372 d)

Average orbital speed

15.94 km/s

Mean anomaly

213°

Mean motion

0° 9 6.48 / day

Inclination

10.9°

Longitude of ascending node

73°

Argument of perihelion

263°

Dimensions

(363 × 249 × 191) ±5 km (MPCD) or (374 × 248 × 194) ±5 km (ADAM)

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Named after

Rhea Silvia

Followed by

88 Thisbe

Follows

86 Semele

Parent body

Sun

Child body

Remus

Diameter

253.051

Mass

14780000000000000000

Orbital period

2375.81511806563

Image

ESO - 87 Sylvia-2 (by).jpg

via Wikidata · CC0