File:110Lydia_(Lightcurve_Inversion).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
- Alphonse Borrelly
- Discovery date
- 19 April 1870
- Pronunciation
- / ˈ l ɪ d i ə /
- Named after
- Lydia
- Alternative designations
- A870 HA; 1899 VA; 1972 YS 1
- Minor planet category
- Main belt Lydia family
- Observation arc
- 145.80 yr (53,255 d)
- Aphelion
- 2.9539 AU (441.90 Gm )
- Perihelion
- 2.51115 AU (375.663 Gm)
- Semi major axis
- 2.7325 AU (408.78 Gm)
- Orbital period sidereal
- 4.52 yr (1649.9 d )
- Average orbital speed
- 17.99 km/s
- Mean anomaly
- 348.344 °
- Mean motion
- 0° 13 5.52 / day
- Inclination
- 5.9645°
- Longitude of ascending node
- 56.871°
- Argument of perihelion
- 283.499°
- Dimensions
- 86.09 ± 2.0 km 86.090 km
via Wikipedia infobox
~2 min read
Encyclopedic overview
110 Lydia is a large belt asteroid with an M-type spectrum, and thus may be metallic in composition, consisting primarily of nickel-iron. It was discovered by French astronomer Alphonse Borrelly on 19 April 1870 and was named for Lydia, the Asia Minor country populated by Phrygians. The Lydia family of asteroids is named after it.
Observations made during 1958–1959 at the McDonald Observatory and in 1969 at the Kitt Peak National Observatory found an uneven light curve with a period of 10.9267 hours. In the late 1990s, a network of astronomers worldwide used light curves to derive spin states and shape models of 10 new asteroids, including (110) Lydia. They obtained a period of 10.92580 hours, with the brightness varying by no more than 0.2 in magnitude.
Excerpted from Wikipedia’s “110 Lydia” article, available under the CC BY-SA 4.0 licence.