File:617_Patroclus_Hubble.jpg · Wikimedia Commons · See Wikimedia Commons
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
- A. Kopff
- Discovery site
- Heidelberg Obs.
- Discovery date
- 17 October 1906
- Pronunciation
- / p ə ˈ t r oʊ k l ə s /
- Named after
- Πάτροκλος Patroklos , ( Greek mythology )
- Alternative designations
- 1906 VY · 1941 XC, 1962 NB
- Minor planet category
- Jupiter trojan , Trojan · background
- Adjectives
- Patroclean / p æ t r ə ˈ k l iː ə n /
- Aphelion
- 5.937 AU
- Perihelion
- 4.480 AU
- Semi major axis
- 5.209 AU
- Orbital period sidereal
- 11.89 yr (4,342 d)
- Mean anomaly
- 319.506 °
- Mean motion
- 0° 4 58.464 / day
- Inclination
- 22.062°
- Longitude of ascending node
- 44.360°
- Argument of perihelion
- 308.306°
- Known satellites
- 1 (Menoetius)
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Patroclus
- Followed by
- 618 Elfriede
- Follows
- 616 Elly
- Parent body
- Sun
- Child body
- Menoetius
- Diameter
- 140.362
- Mass
- 1360000000000000000
- Orbital period
- 4338.731237960914
- Image
- 617 Patroclus Hubble.jpg
Show 22 more facts
- discoverer or inventor
- August Kopff
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A906 UL
- time of discovery or invention
- 1906-10-17
- orbital inclination
- 22.06437618197286
- albedo
- 0.047
- Commons category
- 617 Patroclus
- asteroid spectral type
- P-type asteroid
- density
- 0.88
- temperature
- 110
- rotation period
- 102.8
- color index
- 0.830
- absolute magnitude
- 8.24
- orbital eccentricity
- 0.1393786588467509
- semi-major axis of an orbit
- 5.206064540809859
- periapsis
- 4.480450247242154
- apoapsis
- 5.931678834377563
- longitude of ascending node
- 44.35014598974482
- argument of periapsis
- 308.7674705274295
- mean anomaly
- 42.11893265449262
- time of periapsis
- 2460492.88130884
- epoch
- November 21, 2025
via Wikidata · CC0
~7 min read
Encyclopedic overview
617 Patroclus (/pəˈtroʊkləs/ pə-TROH-kləs) is a large binary Jupiter trojan asteroid. It is a dark D-type asteroid and a slow rotator, due to the 103-hour orbital period of its two components. It is one of five Jupiter trojan asteroids targeted by the Lucy space probe, and is scheduled for a flyby in 2033.
Patroclus was discovered on 17 October 1906, by astronomer August Kopff at the Heidelberg Observatory in Germany, and was named after Patroclus in Greek mythology. It was the second trojan to be discovered and the only member of the Trojan camp named after a Greek figure, as the convention of naming one 'camp' after Greek figures of the Trojan War and the other after Trojan figures had not yet been established.
Excerpted from Wikipedia’s “617 Patroclus” article, available under the CC BY-SA 4.0 licence.