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
- James Edward Keeler
- Discovery site
- Mount Hamilton
- Discovery date
- 6 December 1899
- Pronunciation
- / h æ m ɪ l ˈ t oʊ n i ə /
- Named after
- Mount Hamilton
- Alternative designations
- 1899 FD
- Minor planet category
- main belt
- Observation arc
- 116.35 yr (42497 d)
- Aphelion
- 2.8911284 AU (432.50665 Gm )
- Perihelion
- 2.8064929 AU (419.84536 Gm)
- Semi major axis
- 2.8488107 AU (426.17601 Gm)
- Orbital period sidereal
- 4.81 yr (1756.3 d )
- Mean anomaly
- 9.4952678 °
- Mean motion
- 0° 12 17.923 / day
- Inclination
- 3.223518°
- Longitude of ascending node
- 92.53125°
- Argument of perihelion
- 69.71870°
- Synodic rotation period
- 2.8813 h (0.12005 d )
via Wikipedia infobox
Wikidata facts
- Diameter
- 11.563
- Orbital period
- 1754.735482735096
Show 14 more facts
- provisional designation
- A899 XB
- time of discovery or invention
- 1899-12-06
- albedo
- 0.252
- rotation period
- 2.8813
- absolute magnitude
- 11.86
- orbital eccentricity
- 0.01093721696814711
- semi-major axis of an orbit
- 2.847139986569059
- periapsis
- 2.816000198797266
- apoapsis
- 2.878279774340852
- orbital inclination
- 3.225957165681906
- longitude of ascending node
- 92.42609857811905
- argument of periapsis
- 54.17957423991719
- mean anomaly
- 2.450199243648175
- time of periapsis
- 2460988.5570790204
Sources (2)
via Wikidata · CC0
~1 min read
Article
452 Hamiltonia is an asteroid. It was discovered by James Edward Keeler on 6 December 1899, but was then lost until 1981. Its provisional name was 1899 FD. The asteroid is named for Mount Hamilton, the site of Lick Observatory where Keeler was working when he discovered the asteroid. It was the last asteroid discovery of the 1800s.
L. K. Kristensen at Aarhus University rediscovered 452 Hamiltonia along with 1537 Transylvania along with numerous other small objects in 1981. These rediscoveries left only nine numbered minor planets unobserved since their discoveries: 330 Adalberta (which never existed in the first place), 473 Nolli, 719 Albert, 724 Hapag, 843 Nicolaia, 878 Mildred, 1009 Sirene, 1026 Ingrid, and 1179 Mally. However, by the mid-1980s the only remaining lost asteroids of this group were 719 Albert (rediscovered in 2000), 724 Hapag (rediscovered in 1988), and 878 Mildred (rediscovered in 1991).