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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
- Karl Theodor Robert Luther
- Discovery date
- 23 November 1867
- Pronunciation
- / ær ə ˈ θj uː s ə /
- Minor planet category
- Main belt
- Adjectives
- Arethusian, Arethusean / ˌ ær ə ˈ θj uː z i ə n /
- Observation arc
- 143.53 yr (52424 d)
- Aphelion
- 3.53176 AU (528.344 Gm )
- Perihelion
- 2.59737 AU (388.561 Gm)
- Semi major axis
- 3.06457 AU (458.453 Gm)
- Orbital period sidereal
- 5.36 yr (1959.5 d )
- Average orbital speed
- 16.91 km/s
- Mean anomaly
- 250.185 °
- Mean motion
- 0° 11 1.385 / day
- Inclination
- 12.9955°
- Longitude of ascending node
- 243.038°
- Argument of perihelion
- 154.196°
- Dimensions
- 136.04 ± 10.1 km , 136.04 km , 147 ± 32 km
- Mass
- 2.6 × 10 kg
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Arethusa
- Followed by
- 96 Aegle
- Follows
- 94 Aurora
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 147.969
- Mass
- 2.6
- Orbital period
- 1958.971540806639
- Image
- 95Arethusa (Lightcurve Inversion).png
Show 20 more facts
- discoverer or inventor
- Robert Luther
- site of astronomical discovery
- Düsseldorf-Bilk Observatory
- time of discovery or invention
- 1867-11-23
- asteroid spectral type
- C-type asteroid
- orbital inclination
- 13.00999170570035
- described by source
- Brockhaus and Efron Encyclopedic Dictionary
- albedo
- 0.058
- Commons category
- 95 Arethusa
- provisional designation
- A867 WA
- rotation period
- 8.705
- absolute magnitude
- 7.97
- orbital eccentricity
- 0.1526488584966512
- semi-major axis of an orbit
- 3.063983813073397
- periapsis
- 2.596270181555527
- apoapsis
- 3.531697444591268
- longitude of ascending node
- 242.936547655613
- argument of periapsis
- 152.7664032155228
- mean anomaly
- 156.2604692956698
- time of periapsis
- 2460150.194965824
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
95 Arethusa is a large main-belt asteroid. It was discovered by German astronomer Robert Luther on 23 November 1867, and named after one of the various Arethusas in Greek mythology. Arethusa has been observed occulting a star three times: first on 2 February 1998, and twice in January 2003.
This object is orbiting the Sun with a period of 5.36 years and an eccentricity of 0.15. The cross-section diameter is around 136 km and it is spinning with a rotation period of 8.7 hours. The spectrum matches a C-type asteroid, indicating a dark surface with a primitive carbonaceous composition.
Excerpted from Wikipedia’s “95 Arethusa” article, available under the CC BY-SA 4.0 licence.