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
- R. M. West
- Discovery site
- La Silla Obs.
- Discovery date
- 24 October 1976
- Pronunciation
- / ɪ ˈ p iː ɒ s , - ə s /
- Named after
- Epeius , (Greek mythology)
- Alternative designations
- 1976 UW
- Minor planet category
- Jupiter trojan , Greek · background
- Observation arc
- 40.69 yr (14,862 d)
- Aphelion
- 5.5118 AU
- Perihelion
- 4.9188 AU
- Semi major axis
- 5.2153 AU
- Orbital period sidereal
- 11.91 yr (4,350 d)
- Mean anomaly
- 243.53 °
- Mean motion
- 0° 4 58.08 / day
- Inclination
- 9.1481°
- Longitude of ascending node
- 176.56°
- Argument of perihelion
- 231.58°
- Jupiter moid
- 0.0308 AU
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Epeius
- Followed by
- Q857205
- Follows
- Q845602
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 37.98
- Orbital period
- 4359.341603005558
Show 16 more facts
- discoverer or inventor
- Richard Martin West
- site of astronomical discovery
- La Silla Observatory
- provisional designation
- 1976 UW
- time of discovery or invention
- 1976-10-24
- orbital inclination
- 9.146311579379374
- orbital eccentricity
- 0.05764608773914232
- absolute magnitude
- 10.82
- periapsis
- 4.921479586940429
- longitude of ascending node
- 176.5610164593104
- argument of periapsis
- 233.7076869919075
- apoapsis
- 5.523597412067328
- semi-major axis of an orbit
- 5.222538499503879
- mean anomaly
- 113.3267108958719
- albedo
- 0.064
- time of periapsis
- 2459628.1948734997
- epoch
- November 21, 2025
via Wikidata · CC0
~3 min read
Encyclopedic overview
2148 Epeios /ɪˈpiːɒs/ is a mid-sized Jupiter trojan from the Greek camp, approximately 38 kilometers (24 miles) in diameter. It was discovered on 24 October 1976, by Danish astronomer Richard Martin West at ESO's La Silla Observatory in northern Chile. The dark Jovian asteroid is the principal body of the proposed Epeios family and was named after Epeius from Greek mythology.
Orbit and classification
Excerpted from Wikipedia’s “Q147781” article, available under the CC BY-SA 4.0 licence.