File:53Kalypso_(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
- Karl Theodor Robert Luther
- Discovery date
- 4 April 1858
- Pronunciation
- / k ə ˈ l ɪ p s oʊ /
- Named after
- Calypso
- Minor planet category
- Main belt
- Adjectives
- Kalypsonian / k æ l ɪ p ˈ s oʊ n i ə n / , Kalypsoian / k æ l ɪ p ˈ s oʊ . i ə n /
- Aphelion
- 471.807 million km (3.154 AU)
- Perihelion
- 311.998 million km (2.086 AU)
- Semi major axis
- 391.903 million km (2.620 AU )
- Orbital period sidereal
- 1548.736 d (4.24 a )
- Mean anomaly
- 98.113°
- Inclination
- 5.153°
- Longitude of ascending node
- 143.813°
- Argument of perihelion
- 312.330°
- Dimensions
- 115.4 km
- Mass
- (1.294 ± 0.520/0.412) × 10 kg
- Mean density
- 1.625 ± 0.653/0.517 g/cm
- Synodic rotation period
- 9.036 h
via Wikipedia infobox
~2 min read
Encyclopedic overview
53 Kalypso is a large and very dark main belt asteroid that was discovered by German astronomer Robert Luther on April 4, 1858, at Düsseldorf. It is named after Calypso, a sea nymph in Greek mythology, a name it shares with Calypso, a moon of Saturn.
The orbit of 53 Kalypso places it in a mean motion resonance with the planets Jupiter and Saturn. The computed Lyapunov time for this asteroid is 19,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.
Excerpted from Wikipedia’s “53 Kalypso” article, available under the CC BY-SA 4.0 licence.