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
- J. Palisa
- Discovery site
- Vienna Obs.
- Discovery date
- 19 May 1881
- Pronunciation
- / s t ɪ ˈ f eɪ n i ə /
- Named after
- Princess Stéphanie , (Belgian royalty)
- Alternative designations
- A881 KA · 1925 VE, 1931 FP · 1932 UA, 1943 WB · 1946 MA, 1950 TT 4 · 1961 WB
- Minor planet category
- main-belt · ( inner ) , background
- Observation arc
- 86.28 yr (31,514 days)
- Aphelion
- 2.9543 AU
- Perihelion
- 1.7443 AU
- Semi major axis
- 2.3493 AU
- Orbital period sidereal
- 3.60 yr (1,315 days)
- Mean anomaly
- 239.16 °
- Mean motion
- 0° 16 25.32 / day
- Inclination
- 7.5895°
- Longitude of ascending node
- 257.92°
- Argument of perihelion
- 78.480°
- Dimensions
- 31.04 km (derived) , 31.12 ± 1.5 km , 31.738 ± 0.219 km , 31.96 ± 9.77 km , 32.29 ± 0.33 km , 33 ± 2 km , 35.097 ± 0.260 km , 38.46 ± 5.77 km
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Princess Stéphanie of Belgium
- Followed by
- 221 Eos
- Follows
- 219 Thusnelda
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 31.738
- Orbital period
- 1314.670281933238
- Image
- 220Stephania (Lightcurve Inversion).png
Show 19 more facts
- discoverer or inventor
- Johann Palisa
- site of astronomical discovery
- Vienna Observatory
- provisional designation
- A881 KA
- time of discovery or invention
- 1881-05-19
- orbital inclination
- 7.595643003444502
- albedo
- 0.055
- Commons category
- 220 Stephania
- rotation period
- 18.198
- asteroid spectral type
- X-type asteroid
- absolute magnitude
- 11.2
- orbital eccentricity
- 0.2572217590795616
- semi-major axis of an orbit
- 2.348617428294809
- periapsis
- 1.744501921983902
- apoapsis
- 2.952732934605716
- longitude of ascending node
- 257.8295468789387
- argument of periapsis
- 78.55517740081723
- mean anomaly
- 340.702038224785
- time of periapsis
- 2461070.9734912436
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~3 min read
Encyclopedic overview
220 Stephania is a dark background asteroid from the inner regions of the asteroid belt, approximately 32 km (20 mi) in diameter. It was discovered on 19 May 1881, by Austrian astronomer Johann Palisa at the Vienna Observatory. The C-type asteroid has a rotation period of 18.2 hours. It was named after Princess Stéphanie of Belgium.
Classification and orbit
Excerpted from Wikipedia’s “220 Stephania” article, available under the CC BY-SA 4.0 licence.