File:168_Sibylla.png · 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
- J. C. Watson
- Discovery site
- Ann Arbor
- Discovery date
- 28 September 1876
- Pronunciation
- / s ɪ ˈ b ɪ l ə /
- Named after
- Sibyls
- Alternative designations
- A876 SA; 1911 HF;, 1949 MO
- Minor planet category
- main-belt
- Adjectives
- Sibyllian / s ɪ ˈ b ɪ l i ə n /
- Observation arc
- 136.01 yr (49676 d)
- Aphelion
- 3.6215 AU (541.77 Gm )
- Perihelion
- 3.1417 AU (469.99 Gm)
- Semi major axis
- 3.3816 AU (505.88 Gm)
- Orbital period sidereal
- 6.22 yr (2271.4 d )
- Average orbital speed
- 16.19 km/s
- Mean anomaly
- 171.517 °
- Mean motion
- 0° 9 30.564 / day
- Inclination
- 4.6617°
- Longitude of ascending node
- 205.959°
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- sibyl
- Followed by
- 169 Zelia
- Follows
- 167 Urda
- Parent body
- Sun
- Diameter
- 145.366
- Orbital period
- 2261.559340788031
Show 19 more facts
- discoverer or inventor
- James Craig Watson
- site of astronomical discovery
- Detroit Observatory
- provisional designation
- A876 SA
- time of discovery or invention
- 1876-09-28
- asteroid spectral type
- C-type asteroid
- orbital inclination
- 4.671358318032944
- albedo
- 0.056
- Commons category
- 168 Sibylla
- rotation period
- 47.009
- absolute magnitude
- 8.28
- orbital eccentricity
- 0.07442177745041077
- semi-major axis of an orbit
- 3.371887221729715
- periapsis
- 3.120945381326262
- apoapsis
- 3.622829062133168
- longitude of ascending node
- 205.9050162032167
- argument of periapsis
- 176.7005145317307
- mean anomaly
- 349.27255474695
- time of periapsis
- 2461067.8909833743
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
168 Sibylla is a large main-belt asteroid, discovered by Canadian-American astronomer J. C. Watson on September 28, 1876. It was most likely named for the Sibyls, referring to the Ancient Greek female oracles. Based upon its spectrum this object is classified as a C-type asteroid, which indicates it is very dark and composed of primitive carbonaceous materials. 168 Sibylla is a Cybele asteroid, orbiting beyond most of the main-belt asteroids.
Photometric observations of this asteroid made at the Torino Observatory in Italy during 1990–1991 were used to determine a synodic rotation period of 23.82 ± 0.004 hours. The shape of this slowly rotating object appears to resemble an oblate spheroid.
Excerpted from Wikipedia’s “168 Sibylla” article, available under the CC BY-SA 4.0 licence.