File:321Florentina_(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
- Johann Palisa
- Discovery date
- 15 October 1891
- Pronunciation
- / f l ɒr ə n ˈ t aɪ n ə /
- Minor planet category
- Main belt ( Koronis )
- Observation arc
- 118.15 yr (43153 d)
- Aphelion
- 3.01879 AU (451.605 Gm )
- Perihelion
- 2.7543 AU (412.04 Gm)
- Semi major axis
- 2.88657 AU (431.825 Gm)
- Orbital period sidereal
- 4.90 yr (1,791.3 d)
- Mean anomaly
- 120.99 °
- Mean motion
- 0° 12 3.492 / day
- Inclination
- 2.5876°
- Longitude of ascending node
- 40.224°
- Argument of perihelion
- 37.310°
- Dimensions
- 27.23 ± 1.5 km
- Synodic rotation period
- 2.871 h (0.1196 d )
- Geometric albedo
- 0.2296 ± 0.028
via Wikipedia infobox
~2 min read
Encyclopedic overview
321 Florentina is an S-type (stony) main belt asteroid with a diameter of 28 km. It was discovered by Johann Palisa on 15 October 1891 in Vienna. He named the asteroid for his daughter, Florentine. Between 1874 and 1923, Palisa discovered a total of 122 asteroids.
This asteroid is a dynamic member of the Koronis family. It is orbiting the Sun at a distance of 2.887 AU with an eccentricity (ovalness) of 0.046 and an orbital period of 4.90 yr. The orbital plane is inclined at an angle of 2.59° to the plane of the ecliptic. Photometric data collected during the asteroid opposition of 2011 was used to construct a light curve that displayed a rotation period of 2.870±0.001 h. This is consistent with previous rotation estimates.
Excerpted from Wikipedia’s “321 Florentina” article, available under the CC BY-SA 4.0 licence.