File:140_Siwa.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
- J. Palisa
- Discovery site
- Austrian Naval Obs.
- Discovery date
- 13 October 1874
- Pronunciation
- / ˈ ʃ iː w ə /
- Named after
- Živa
- Alternative designations
- A874 TB; 1948 AL
- Minor planet category
- Main belt
- Observation arc
- 139.10 yr (50805 d)
- Aphelion
- 3.3224 AU (497.02 Gm )
- Perihelion
- 2.14323 AU (320.623 Gm)
- Semi major axis
- 2.73283 AU (408.826 Gm)
- Orbital period sidereal
- 4.52 yr (1650.1 d )
- Average orbital speed
- 17.80 km/s
- Mean anomaly
- 200.674 °
- Mean motion
- 0° 13 5.398 / day
- Inclination
- 3.1860°
- Longitude of ascending node
- 107.263°
- Argument of perihelion
- 196.711°
via Wikipedia infobox
~2 min read
Encyclopedic overview
140 Siwa is a large and dark main-belt asteroid that was discovered by Austrian astronomer Johann Palisa on October 13, 1874. It was named after Živa (Šiwa), a Slavic goddess of fertility. This object is orbiting the Sun at a distance of 2.73 AU with an eccentricity of 0.22 and an orbital period of 4.52 years. The orbital plane is inclined at an angle of 3.2°.
A 2004 study of the spectrum of 140 Siwa matched a typical C-type asteroid with typical carbonaceous chondrite makeup. There are no absorption features of mafic minerals found. The classification was later revised to a P-type asteroid.
Excerpted from Wikipedia’s “140 Siwa” article, available under the CC BY-SA 4.0 licence.