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
- Max Wolf
- Discovery site
- Heidelberg
- Discovery date
- 31 March 1916
- Pronunciation
- / s ɪ s ɪ ˈ ɡ æ m b ɪ s /
- Alternative designations
- 1916 ZG; A913 JB;, 1937 QE; 1939 FA1;, 1969 FN
- Observation arc
- 100.04 yr (36540 d)
- Aphelion
- 2.4213 AU (362.22 Gm )
- Perihelion
- 2.0211 AU (302.35 Gm)
- Semi major axis
- 2.2212 AU (332.29 Gm)
- Orbital period sidereal
- 3.31 yr (1209.2 d )
- Mean anomaly
- 176.61 °
- Mean motion
- 0° 17 51.828 / day
- Inclination
- 3.6456°
- Longitude of ascending node
- 255.028°
- Argument of perihelion
- 218.602°
- Earth moid
- 1.03763 AU (155.227 Gm)
- Jupiter moid
- 2.65835 AU (397.683 Gm)
- Mean radius
- 8.315 ± 0.7 km
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 824 Anastasia
- Follows
- 822 Lalage
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 14.719
- Orbital period
- 1209.190049153357
Show 17 more facts
- discoverer or inventor
- Max Wolf
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A916 GK
- time of discovery or invention
- 1916-03-31
- orbital inclination
- 3.647208426033793
- albedo
- 0.298
- rotation period
- 146.0
- absolute magnitude
- 11.2
- orbital eccentricity
- 0.09013175772593739
- semi-major axis of an orbit
- 2.221249919764297
- periapsis
- 2.021044760147344
- apoapsis
- 2.42145507938125
- longitude of ascending node
- 254.9633747465689
- argument of periapsis
- 218.6638430756906
- mean anomaly
- 108.7299316868319
- time of periapsis
- 2460635.291245998
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
823 Sisigambis is an asteroid belonging to the Flora family in the Main Belt. Its diameter is about 17 km, and it has an albedo of 0.179. Its rotation period is unknown but appears to be greater than at least 12 hours. The asteroid is named after Sisygambis, the mother of Darius III of Persia.
Captured by Alexander the Great at the Battle of Issus, Sisygambis became devoted to him, and Alexander referred to her as "mother". Having learned of Alexander's death, she had become depressed and had herself sealed into her rooms and refused to eat. She is said to have died of grief and starvation four days later.
Excerpted from Wikipedia’s “823 Sisigambis” article, available under the CC BY-SA 4.0 licence.