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
- Joel Hastings Metcalf
- Discovery site
- Taunton, Massachusetts
- Discovery date
- 5 May 1907
- Pronunciation
- / ˈ m ɔɪ r ə /
- Named after
- Moirae
- Alternative designations
- 1907 ZQ
- Observation arc
- 110.22 yr (40257 d)
- Aphelion
- 3.1701 AU (474.24 Gm )
- Perihelion
- 2.3005 AU (344.15 Gm)
- Semi major axis
- 2.7353 AU (409.20 Gm)
- Orbital period sidereal
- 4.52 yr (1652.4 d )
- Mean anomaly
- 54.7967 °
- Mean motion
- 0° 13 4.332 / day
- Inclination
- 7.7123°
- Longitude of ascending node
- 103.208°
- Argument of perihelion
- 128.586°
- Mean radius
- 32.72 ± 0.7 km
- Synodic rotation period
- 9.875 h (0.4115 d )
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Moirae
- Followed by
- Q156052
- Follows
- Q156043
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 59.594
- Orbital period
- 1650.663811512448
Show 18 more facts
- discoverer or inventor
- Joel Hastings Metcalf
- provisional designation
- A906 BF
- time of discovery or invention
- 1907-05-05
- orbital inclination
- 7.708736571735923
- site of astronomical discovery
- Taunton
- albedo
- 0.06
- rotation period
- 9.8768
- asteroid spectral type
- C-type asteroid
- absolute magnitude
- 10.1
- orbital eccentricity
- 0.1622812178436305
- semi-major axis of an orbit
- 2.733422734021495
- periapsis
- 2.28983956386302
- apoapsis
- 3.177005904179969
- longitude of ascending node
- 103.0896672188744
- argument of periapsis
- 128.4390357922159
- mean anomaly
- 75.98749051027288
- time of periapsis
- 2460652.0838869084
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
638 Moira, also known as A907 JG, is a minor planet orbiting the Sun. First observed in 1906, 638 Moira was discovered to be an orbital body in 1907 by Joel Hastings Metcalf in Taunton, England. 638 Moira is a little over 59.5 km across and rotates once every 10 hours. Its farthest point from the sun is a little over 3au during its 4.5 year orbit, and it is classed as an L-type asteroid (SMASSII).
References
Excerpted from Wikipedia’s “Q156051” article, available under the CC BY-SA 4.0 licence.