142 Polana

Also known as (142) Polana, Polana

main-belt asteroid

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

Small body data

142 Polana (A875 BA)

Orbit class: Main-belt Asteroid
Diameter: 54.812 km
Albedo: 0.047
Rotation period: 9.764 h
Absolute magnitude: 10.530 H
Earth MOID: 1.090 AU

via NASA/JPL Small-Body Database

Key facts

Discovered by: J. Palisa
Discovery site: Austrian Naval Obs.
Discovery date: 28 January 1875
Named after: Pula
Alternative designations: A875 BA; 1923 WA;, 1954 BH; 1956 XZ;, 1963 SA
Minor planet category: Asteroid belt
Observation arc: 117.65 yr (42971 d)
Aphelion: 2.7444 AU (410.56 Gm )
Perihelion: 2.0934 AU (313.17 Gm)
Semi major axis: 2.4189 AU (361.86 Gm)
Orbital period sidereal: 3.76 yr (1374.1 d )
Average orbital speed: 19.07 km/s
Mean anomaly: 140.92 °
Mean motion: 0° 15 43.128 / day
Inclination: 2.2379°
Longitude of ascending node: 291.27°
Argument of perihelion: 292.00°
Dimensions: 55.29 ± 1.6 km , 55.3 ± 1.6

via Wikipedia infobox

~2 min read

Encyclopedic overview

142 Polana is a very dark asteroid from the asteroid belt. It was discovered by Johann Palisa on January 28, 1875, and named after the city of Pola (now Pula, Croatia), home of the Austrian Naval Observatory where he made the discovery.

It is a major member of the eponymously named Polana family, which is a subgroup of the Nysa family. The asteroid has an estimated diameter of about 55.3 km and a low albedo of 0.045. It is orbiting at a distance of 2.419 times the separation of the Earth from the Sun, with an orbital period of 3.76 years and an eccentricity of 0.14.

Excerpted from Wikipedia’s “142 Polana” article, available under the CC BY-SA 4.0 licence.