File:87_Sylvia_VLT_(2021),_deconvolved.pdf · 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
- Norman Robert Pogson
- Discovery date
- 16 May 1866
- Pronunciation
- / ˈ s ɪ l v i ə / SIL -vee-ə
- Named after
- Rhea Silvia
- Alternative designations
- A909 GA
- Minor planet category
- main belt · ( outside core ) , Sylvia · Cybele
- Adjectives
- Sylvian ( / ˈ s ɪ l v i ə n / SIL -vee-ən )
- Aphelion
- 3.81 AU (560 million km)
- Perihelion
- 3.15 AU (480 million km)
- Semi major axis
- 3.48 AU (520 million km)
- Orbital period sidereal
- 6.5 a (2372 d)
- Average orbital speed
- 15.94 km/s
- Mean anomaly
- 213°
- Mean motion
- 0° 9 6.48 / day
- Inclination
- 10.9°
- Longitude of ascending node
- 73°
- Argument of perihelion
- 263°
- Dimensions
- (363 × 249 × 191) ±5 km (MPCD) or (374 × 248 × 194) ±5 km (ADAM)
via Wikipedia infobox
Wikidata facts
- Diameter
- 253.051
- Mass
- 14780000000000000000
- Orbital period
- 2375.81511806563
- Image
- ESO - 87 Sylvia-2 (by).jpg
Show 20 more facts
- Commons category
- 87 Sylvia
- provisional designation
- A866 KA
- time of discovery or invention
- 1866-05-16
- orbital inclination
- 10.87247390226396
- Commons gallery
- (87) Sylvia
- density
- 1.2
- rotation period
- 5.184
- apparent magnitude
- 12.87
- albedo
- 0.046
- temperature
- 151
- surface gravity
- 0.0729
- absolute magnitude
- 6.94
- orbital eccentricity
- 0.09433757215082976
- semi-major axis of an orbit
- 3.484518782214823
- periapsis
- 3.155797740186711
- apoapsis
- 3.813239824242936
- longitude of ascending node
- 73.01146030211659
- argument of periapsis
- 265.8265584708386
- mean anomaly
- 94.95962368177054
- time of periapsis
- 2460373.815251253
Sources (2)
via Wikidata · CC0
~4 min read
Article
87 Sylvia is one of the largest asteroids (approximately tied for 7th place, to within measurement uncertainties). It is the parent body of the Sylvia family and member of Cybele group located beyond the main asteroid belt (see minor-planet groups). Sylvia was the first asteroid known to possess more than one moon.
Discovery and naming