File:000748-asteroid_shape_model_(748)_Simeïsa.png · Wikimedia Commons · See Wikimedia Commons
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
- G. Neujmin
- Discovery site
- Simeiz Obs.
- Discovery date
- 14 March 1913
- Named after
- Simeiz / Simeiz Obs. , (Town and Observatory)
- Alternative designations
- A913 EL · 1925 QG, 1936 BG · 1941 SU, 1942 XU · 1944 DC, 1951 CX · 1957 UL 1 , 1963 MC · 1913 RD
- Minor planet category
- main-belt · ( outer ) Hilda
- Observation arc
- 99.96 yr (36,509 d)
- Aphelion
- 4.6898 AU
- Perihelion
- 3.2045 AU
- Semi major axis
- 3.9472 AU
- Orbital period sidereal
- 7.84 yr (2,864 d)
- Mean anomaly
- 324.14 °
- Mean motion
- 0° 7 32.52 / day
- Inclination
- 2.2587°
- Longitude of ascending node
- 265.46°
- Argument of perihelion
- 177.73°
- Jupiter moid
- 0.5637 AU
- Dimensions
- ( 109.7 km × 93.2 km )
via Wikipedia infobox
Wikidata facts
- Instance of
- asteroid
- Named after
- Simeiz
- Followed by
- 749 Malzovia
- Follows
- 747 Winchester
- Parent body
- Sun
- Diameter
- 103.714
- Orbital period
- 2869.855119235257
Show 20 more facts
- discoverer or inventor
- Grigory Neujmin
- site of astronomical discovery
- Simeiz Observatory
- provisional designation
- A913 EL
- time of discovery or invention
- 1913-03-14
- orbital inclination
- 2.259061234305446
- apparent magnitude
- 16.55
- asteroid spectral type
- P-type asteroid
- rotation period
- 11.905
- Commons category
- 748 Simeïsa
- albedo
- 0.041
- absolute magnitude
- 9.08
- orbital eccentricity
- 0.1896759215168103
- semi-major axis of an orbit
- 3.95221926173862
- periapsis
- 3.20257843123186
- apoapsis
- 4.701860092245381
- longitude of ascending node
- 265.3874501302376
- argument of periapsis
- 177.987911389391
- mean anomaly
- 214.7588854188787
- time of periapsis
- 2462158.3359894557
- epoch
- November 21, 2025
Sources (2)
via Wikidata · CC0
~4 min read
Encyclopedic overview
748 Simeïsa (prov. designation: A913 EL or 1913 RD) is a very large Hilda asteroid from the outermost regions of the asteroid belt, approximately 104 kilometers (65 miles) in diameter. It was discovered on 14 March 1913, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. The dark P-type asteroid has a rotation period of 11.9 hours and a shape that is reminiscent of a tetrahedron. It was the first asteroid discovery made in Russia and named after the discovering observatory and its nearby Crimean town, Simeiz.
Orbit and classification
Excerpted from Wikipedia’s “748 Simeïsa” article, available under the CC BY-SA 4.0 licence.