File:202_Chryseïs.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
- C. H. F. Peters
- Discovery date
- 11 September 1879
- Pronunciation
- / k r aɪ ˈ s iː ɪ s /
- Named after
- Chryseis
- Alternative designations
- A879 RA, A901 TA, 1935 BL
- Minor planet category
- Main belt
- Observation arc
- 136.57 yr (49881 d)
- Aphelion
- 3.3859 AU (506.52 Gm )
- Perihelion
- 2.7567 AU (412.40 Gm)
- Semi major axis
- 3.0713 AU (459.46 Gm)
- Orbital period sidereal
- 5.38 yr (1966.0 d )
- Average orbital speed
- 16.99 km/s
- Mean anomaly
- 11.1527 °
- Mean motion
- 0° 10 59.196 / day
- Inclination
- 8.8535°
- Longitude of ascending node
- 136.848°
- Argument of perihelion
- 1.3159°
- Dimensions
- 86.15 ± 2.4 km
via Wikipedia infobox
~1 min read
Encyclopedic overview
202 Chryseïs is a large, lightly coloured main belt asteroid that is probably composed of silicate rocks. It was discovered by C. H. F. Peters on September 11, 1879, in Clinton, New York, and was named after the mythical Trojan woman Chryseis. 202 Chryseïs is orbiting the Sun with a semimajor axis of 3.07 AU and an eccentricity of 0.102, which brings it as close to the Sun as 2.76 AU and as far away as 3.39 AU during the course of its 5.38 year orbital period. The orbital plane is inclined at an angle of 8.85° relative to the plane of the ecliptic.
The rotation period for this asteroid is close to a day long, so the construction of a complete light curve requires photometric observations from multiple locations at widely spaced latitudes. This task was completed in January and February, 2011, yielding a synodic rotation period of 23.670 ± 0.001 h, with a brightness variation of 0.20 ± 0.02 in magnitude. This is a stony, S-type asteroid. Based on infrared observations, it has a diameter of 86.15±2.4 km.
Excerpted from Wikipedia’s “202 Chryseïs” article, available under the CC BY-SA 4.0 licence.