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
- August Kopff
- Discovery site
- Heidelberg
- Discovery date
- 21 March 1907
- Alternative designations
- 1907 YJ
- Observation arc
- 109.08 yr (39842 d)
- Aphelion
- 3.0226 AU (452.17 Gm )
- Perihelion
- 2.5641 AU (383.58 Gm)
- Semi major axis
- 2.7933 AU (417.87 Gm)
- Orbital period sidereal
- 4.67 yr (1705.2 d )
- Mean anomaly
- 217.70 °
- Mean motion
- 0° 12 39.996 / day
- Inclination
- 18.917°
- Longitude of ascending node
- 224.709°
- Argument of perihelion
- 277.857°
- Mean radius
- 28.825 ± 0.6 km
- Synodic rotation period
- 5.899 h (0.2458 d )
- Geometric albedo
- 0.1760 ± 0.008
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Followed by
- 632 Pyrrha
- Follows
- Q155976
- Parent body
- Sun
- Minor-planet group
- asteroid belt
- Diameter
- 50.491
- Orbital period
- 1703.870205846139
- Image
- 631Philippina (Lightcurve Inversion).png
Show 19 more facts
- discoverer or inventor
- August Kopff
- site of astronomical discovery
- Heidelberg-Königstuhl State Observatory
- provisional designation
- A907 FD
- time of discovery or invention
- 1907-03-21
- orbital inclination
- 18.90031937531656
- Commons category
- 631 Philippina
- albedo
- 0.229
- rotation period
- 5.899
- asteroid spectral type
- S-type asteroid
- absolute magnitude
- 8.63
- orbital eccentricity
- 0.08504914716130516
- semi-major axis of an orbit
- 2.791849831324193
- periapsis
- 2.554405384167637
- apoapsis
- 3.029294278480749
- longitude of ascending node
- 224.5231065753564
- argument of periapsis
- 279.3936342259086
- mean anomaly
- 214.2025643422529
- time of periapsis
- 2461690.5552964057
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~1 min read
Encyclopedic overview
631 Philippina is a minor planet orbiting the Sun that was discovered by German astronomer August Kopff on March 21, 1907.
Photometric of this asteroid made in 1981 gave a light curve with a period of 5.92 ± 0.01 hours with a brightness variation of 0.20 in magnitude. In 2007 lightcurve data showed that it rotates every 5.899 ± 0.001 hours.
Excerpted from Wikipedia’s “631 Philippina” article, available under the CC BY-SA 4.0 licence.