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
- M. F. Wolf
- Discovery site
- Heidelberg
- Discovery date
- 17 December 1905
- Pronunciation
- / s ə ˈ l iː n iː /
- Alternative designations
- 1905 SE
- Observation arc
- 110.29 yr (40283 d)
- Aphelion
- 3.4971 AU (523.16 Gm )
- Perihelion
- 2.9628 AU (443.23 Gm)
- Semi major axis
- 3.2300 AU (483.20 Gm)
- Orbital period sidereal
- 5.81 yr (2120.3 d )
- Mean anomaly
- 45.310 °
- Mean motion
- 0° 10 11.244 / day
- Inclination
- 3.6614°
- Longitude of ascending node
- 99.154°
- Argument of perihelion
- 334.542°
- Mean radius
- 22.895 ± 1.6 km
- Synodic rotation period
- 9.47 h (0.395 d )
- Geometric albedo
- 0.1218 ± 0.019
via Wikipedia infobox
Wikidata facts
- Diameter
- 48.204
- Orbital period
- 2119.021172718187
Show 14 more facts
- provisional designation
- 1950 RQ1
- time of discovery or invention
- 1905-12-17
- orbital inclination
- 3.671079621205674
- albedo
- 0.082
- absolute magnitude
- 10.39
- rotation period
- 9.494
- orbital eccentricity
- 0.0879622848610157
- semi-major axis of an orbit
- 3.228676847853059
- periapsis
- 2.944675055238042
- apoapsis
- 3.512678640468076
- longitude of ascending node
- 98.89253581923838
- argument of periapsis
- 339.3220689319764
- mean anomaly
- 257.6192737510742
- time of periapsis
- 2461603.130351666
Sources (3)
via Wikidata · CC0
~1 min read
Article
580 Selene is a minor planet orbiting the Sun in the asteroid belt. The name Selene is that of an ancient Greek goddess of the Moon. The name may have been inspired by the asteroid's provisional designation 1905 SE.
This body orbits the Sun nearly midway between the orbits of Mars and Jupiter. The orbital eccentricity is slightly lower than that of Mars. Based on its light curve, Selene has an estimated rotation period of 0.3947±0.0004 days, or just under 9.5 hours. During each rotation, the apparent magnitude varies by 0.27. The approximate diameter of this asteroid is 46 km. (Some sources list a diameter of up to 56 km.) The albedo is about 7%, comparable to that of the Earth's Moon.