21774 O'Brien

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

21774 O'Brien (1999 RR217)

Orbit class

Main-belt Asteroid

Rotation period

27.431 h

Absolute magnitude

15.700 H

Earth MOID

1.170 AU

via NASA/JPL Small-Body Database

Wikidata facts

Instance of

asteroid

Followed by

21775 Tsiganis

Parent body

Sun

Minor-planet group

asteroid belt

Orbital period

1307.197752547638

via Wikidata · CC0