File:Орбита_астероида_397.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
- Auguste Charlois
- Discovery date
- 19 December 1894
- Pronunciation
- / v i ˈ ɛ n ə /
- Named after
- Vienna
- Alternative designations
- 1894 BM
- Minor planet category
- Main belt
- Observation arc
- 117.45 yr (42,900 d)
- Aphelion
- 3.28657 AU (491.664 Gm )
- Perihelion
- 1.98686 AU (297.230 Gm)
- Semi major axis
- 2.63671 AU (394.446 Gm)
- Orbital period sidereal
- 4.28 yr (1,563.8 d)
- Mean anomaly
- 202.358 °
- Mean motion
- 0° 13 48.731 / day
- Inclination
- 12.8534°
- Longitude of ascending node
- 227.935°
- Argument of perihelion
- 139.975°
- Dimensions
- 49.032 ± 1.055 km
- Synodic rotation period
- 15.48 h (0.645 d )
via Wikipedia infobox
~1 min read
Encyclopedic overview
397 Vienna is a typical Main belt asteroid. It was discovered by French astronomer Auguste Charlois on 19 December 1894 in Nice. It was most likely named after the city of Vienna, Austria. This object is orbiting the Sun at a distance of 2.64 AU with an orbital eccentricity (ovalness) of 0.246 and a period of 4.28 yr. The orbital plane is inclined at an angle of 12.85° to the ecliptic.
Photometric observations from multiple sites during 2017 were combined to produce an irregular light curve showing a rotation period of 15.461±0.001 h with a luminosity amplitude of 0.16±0.02 in magnitude. This result is consistent with previous measurements. The Tholen spectral type of this object is S and the SMASSII spectral type is K. Although the 'S' class suggests a stony composition, the latter class is consistent with carbonaceous chondrite meteorites. Infrared observations from NEOWISE indicate a diameter of 49 km.
Excerpted from Wikipedia’s “Q152419” article, available under the CC BY-SA 4.0 licence.