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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
- Max Wolf
- Discovery date
- 4 March 1892
- Pronunciation
- / ˌ h aɪ d əl ˈ b ɜːr ɡ ə /
- Named after
- Heidelberg
- Minor planet category
- Main belt
- Adjectives
- Heidelergian / ˌ h aɪ d əl ˈ b ɜːr dʒ i ə n , - ɡ i ə n /
- Observation arc
- 117.86 yr (43050 d)
- Aphelion
- 3.7223 AU (556.85 Gm )
- Perihelion
- 2.69998 AU (403.911 Gm)
- Semi major axis
- 3.21115 AU (480.381 Gm)
- Orbital period sidereal
- 5.75 yr (2101.8 d )
- Mean anomaly
- 7.2090 °
- Mean motion
- 0° 10 16.608 / day
- Inclination
- 8.5545°
- Longitude of ascending node
- 344.881°
- Argument of perihelion
- 68.563°
- Dimensions
- 75.72 ± 1.7 km
- Synodic rotation period
- 6.737 h (0.2807 d )
via Wikipedia infobox
~1 min read
Encyclopedic overview
325 Heidelberga is a large main belt asteroid that was discovered by German astronomer Max Wolf on 4 March 1892 in Heidelberg. It is orbiting the Sun at a distance of 3.21 AU with an eccentricity (oval shape) of 0.159. The orbital plane is inclined at an angle of 8.55° to the ecliptic.
Based upon its spectrum, 325 Heidelberga is classified as an M-type asteroid. No absorption features have been detected with certainty, indicating it most likely has a nickel-iron or enstatite chondrite composition. A weak feature in the near infrared spectrum indicates the presence of low-iron orthopyroxene on the asteroid surface.
Excerpted from Wikipedia’s “325 Heidelberga” article, available under the CC BY-SA 4.0 licence.