121 Hermione

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

James Craig Watson

Discovery date

12 May 1872

Pronunciation

/ h ɜːr ˈ m aɪ . ə n iː /

Named after

Hermione , (Greek mythology)

Alternative designations

A872 JA; 1970 VE

Minor planet category

main-belt · Cybele

Adjectives

Hermionean / h ɜːr m aɪ . ə ˈ n iː ə n /

Observation arc

145.96 yr (53,312 d)

Aphelion

3.9067 AU

Perihelion

2.9889 AU

Semi major axis

3.4478 AU

Orbital period sidereal

6.40 yr (2,338 d)

Mean anomaly

157.08 °

Mean motion

0° 9 14.4 / day

Inclination

7.5975°

Longitude of ascending node

73.127°

Argument of perihelion

298.18°

Known satellites

S/2002 (121) 1

via Wikipedia infobox

Wikidata facts

Instance of

asteroid

Named after

Hermione

Followed by

122 Gerda

Follows

120 Lachesis

Parent body

Sun

Child body

S/2002 (121) 1

Minor-planet group

asteroid belt

Diameter

209.0

Mass

5.38

Orbital period

2347.725318585089

via Wikidata · CC0