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
- B. Jekhovsky
- Discovery site
- Algiers Obs.
- Discovery date
- 10 November 1922
- Pronunciation
- / ə ˈ p ɛ l ə /
- Named after
- Paul Appell , (French mathematician)
- Alternative designations
- 1922 MT · 1955 QJ 1
- Minor planet category
- main-belt · Themis
- Observation arc
- 76.56 yr (27,964 days)
- Aphelion
- 3.8829 AU
- Perihelion
- 2.4017 AU
- Semi major axis
- 3.1423 AU
- Orbital period sidereal
- 5.57 yr (2,035 days)
- Mean anomaly
- 308.57 °
- Mean motion
- 0° 10 36.84 / day
- Inclination
- 1.5748°
- Longitude of ascending node
- 41.726°
- Argument of perihelion
- 337.28°
- Dimensions
- 20.431 ± 0.215 km , 20.44 ± 0.33 km , 21.7 ± 2.2 km , 22 ± 2 km , 25.77 km (derived) , 25.91 ± 1.2 km ( IRAS :18) , 30.09 ± 0.37 km
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Paul Appell
- Followed by
- 989 Schwassmannia
- Follows
- 987 Wallia
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 20.431
- Orbital period
- 2031.245012369684
Show 17 more facts
- discoverer or inventor
- Benjamin Jekhowsky
- site of astronomical discovery
- Center of Research in Astronomy, Astrophysics and Geophysics
- provisional designation
- A922 VC
- time of discovery or invention
- 1922-11-10
- albedo
- 0.097
- rotation period
- 120.0
- absolute magnitude
- 11.62
- orbital eccentricity
- 0.2372199656791333
- semi-major axis of an orbit
- 3.138888749101202
- periapsis
- 2.394281667768797
- apoapsis
- 3.883495830433606
- orbital inclination
- 1.57329747504221
- longitude of ascending node
- 41.68939979017532
- argument of periapsis
- 336.5536506391591
- mean anomaly
- 155.8721372192022
- time of periapsis
- 2460121.0152741834
- epoch
- November 21, 2025
Sources (3)
via Wikidata · CC0
~3 min read
Encyclopedic overview
988 Appella, provisional designation 1922 MT, is a dark Themistian asteroid and slow rotator from the outer region of the asteroid belt, approximately 26 kilometers in diameter. It was discovered on 10 November 1922, by Russian–French astronomer Benjamin Jekhowsky at Algiers Observatory in Algeria, North Africa. The asteroid was later named after French mathematician Paul Émile Appel.
Classification and orbit
Excerpted from Wikipedia’s “988 Appella” article, available under the CC BY-SA 4.0 licence.