Q152091

Also known as Cruithne

Aten asteroid and a co-orbital object with Earth

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: Duncan Waldron
Discovery date: 10 October 1986
Pronunciation: English: / k r u ˈ iː n j ə / kroo- EEN -yə , Irish: [ ˈkɾˠɪ(h)nʲə, ˈkɾˠʊnʲə ]
Named after: Cruthin
Alternative designations: 1983 UH; 1986 TO
Minor planet category: NEO Aten horseshoe Venus-crosser Mars-crosser
Observation arc: 16087 days (44.04 yr)
Aphelion: 1.5114 AU (226,100,000 km )
Perihelion: 0.48405 AU (72,413,000 km)
Semi major axis: 0.99774 AU (149,260,000 km)
Eccentricity: 0.51485, (213000 wrt Earth)
Orbital period sidereal: 1.00 yr (364.02 d )
Average orbital speed: 27.73 km/s
Mean anomaly: 257.46 °
Mean motion: 0° 59 20.436 / day
Inclination: 19.805°
Longitude of ascending node: 126.23°
Argument of perihelion: 43.831°

via Wikipedia infobox

Wikidata facts

Diameter: 2.071
Mass: 130000000000000
Orbital period: 364.0450994690112
Image: Cruithne.jpg

Show 19 more facts

provisional designation: 1986 TO
time of discovery or invention: 1986-10-10
orbital inclination: 19.80229712950891
Commons gallery: (3753) Cruithne
semi-major axis of an orbit: 0.9977870006741981
periapsis: 0.4840506808946771
apoapsis: 1.511523320453719
longitude of ascending node: 126.1891671662289
argument of periapsis: 43.8792989900313
mean anomaly: 344.3639422567854
density: 2
rotation period: 27.3099
absolute magnitude: 15.44
apparent magnitude: 16.46
orbital eccentricity: 0.5148757394437818
catalog code: 1983 UH
albedo: 0.365
Commons category: 3753 Cruithne
time of periapsis: 2461016.3117505456

Sources (3)

via Wikidata · CC0

~8 min read

Article

3753 Cruithne is a Q-type, Aten asteroid in orbit around the Sun in 1:1 orbital resonance with Earth, making it a co-orbital object. It is an asteroid that, relative to Earth, orbits the Sun in a bean-shaped orbit that effectively describes a horseshoe, and that can change into a quasi-satellite orbit. Cruithne does not orbit Earth and at times it is on the other side of the Sun, placing Cruithne well outside of Earth's Hill sphere. Its orbit takes it near the orbit of Mercury and outside the orbit of Mars. Cruithne orbits the Sun in about one Earth year, but it takes 770 years for the series to complete a horseshoe-shaped movement around Earth.

The asteroid takes its name from the Cruithne, a people mentioned in early Irish annals.