1915 Quetzálcoatl, provisional designation , is a very eccentric, stony asteroid classified as

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

, about half a kilometer in diameter. It was discovered on 9 March 1953, by American astronomer

Albert George Wilson Albert George Wilson (July 28, 1918 – August 27, 2012) was an American astronomer and a discoverer of minor planets. He was born in Houston, Texas. He received his Ph.D. in mathematics from Caltech in 1947; his thesis title was ''Axiall ...

at Palomar Observatory, California. It was named for Quetzalcoatl from Aztec mythology.

Orbit and classification

''Quetzálcoatl'' is an

Amor asteroid The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor . The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth (i.e., the objects do not cross Earth's orbi ...

– a subgroup of near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it – and a member of the Alinda family of highly eccentric asteroids. It orbits the Sun at a distance of 1.1–4.0 AU with a period of around 4 years. The

osculating orbit In astronomy, and in particular in astrodynamics, the osculating orbit of an object in space at a given moment in time is the gravitational Kepler orbit (i.e. an elliptic or other conic one) that it would have around its central body if pertu ...

as of 2017 has a period just over 4 years, but the period varies because Quetzálcoatl is near the 3:1

orbital resonance In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationsh ...

with Jupiter (and possibly because it is near the 1:4 resonance with Earth). Its orbit has an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.57 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 20 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

. When it was discovered in March 1953 it had a

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

around 15, but in recent times its magnitude rarely dips below 20 because even when it is near

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elli ...

it is far from Earth. After the 1953 close approach there were others every four years until March 1981, but the next one will not be until 77 years (19 orbits averaging 4,05 years) later, in February 2062, when its magnitude will be about 17. Its magnitude will get to around 16 (a bit less bright than in 1953) 52 years (13 orbits) later in 2114. Another close approach will occur 39 years (10 orbits) later in 2153 (average period 3.9 years). In the 285 years from 1953 to 2238 it makes 72 orbits, giving an average period of 3.96 years (quite close to a third of Jupiter's period, which comes to 3.95 years).NASA ephemeris calculator
/ref> Its Earth ''

Minimum orbit intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits o ...

'' (MOID) is 0.1102 AU which translates into 42.9 lunar distances. On 24 February 2062, it will make a close approach and pass by Earth at a distance of .

Physical characteristics

In the

Tholen classification An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ...

, ''Quetzálcoatl'' is classified as a rare SMU-subtype of the broader

S-type asteroid S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the secon ...

s. Its mean-diameter is between 0.4 and 0.5 kilometers. It has a rotation period of 4.9 hours and an

albedo Albedo (; ) is the measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that refl ...

of 0.21–0.31. In 1981, this object was observed with

radar Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

from the Arecibo Observatory at a distance of 0.09 AU. The measured radar cross-section was 0.02 km².

Naming

This

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

is named after the "feathered serpent" Quetzalcoatl, the

Mesoamerican Mesoamerica is a historical region and cultural area in southern North America and most of Central America. It extends from approximately central Mexico through Belize, Guatemala, El Salvador, Honduras, Nicaragua, and northern Costa Rica. Withi ...

deity of wisdom and culture who brought learning to the Toltec people. The official was published by the Minor Planet Center on 1 June 1975 ().

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend * * * {{DEFAULTSORT:Quetzalcoatl 001915 001915 Discoveries by Albert George Wilson Named minor planets 001915 001915 19530309