8661 Ratzinger, provisional designation , is an Eoan

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

from the outer region of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

, approximately 13.4 kilometers in diameter. It was discovered on 14 October 1990, by German astronomers Lutz Schmadel and

Freimut Börngen Freimut Börngen (; 17 October 1930 – 19 June 2021) was a German astronomer and a prolific discoverer of minor planets. A few sources give his first name wrongly as "Freimuth". The Minor Planet Center credits him as F. Borngen. He studied gal ...

at the Karl Schwarzschild Observatory in Tautenburg, eastern Germany. The asteroid was named after Cardinal Joseph Ratzinger, who became

Pope Benedict XVI Pope BenedictXVI (born Joseph Alois Ratzinger; 16 April 1927 – 31 December 2022) was head of the Catholic Church and sovereign of the Vatican City State from 19 April 2005 until his resignation on 28 February 2013. Benedict's election as p ...

Orbit and classification

''Ratzinger'' is a member of the Eos family (), the largest

asteroid family An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An ...

in the outer main belt consisting of nearly 10,000 asteroids. It orbits the Sun at a distance of 2.9–3.1 AU once every 5 years and 3 months (1,906 days). 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 0.04 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 11 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

. In October 1969, it was first identified as at Crimea–Nauchnij. The body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins at Leoncito in 1974, when it was identified as , 16 years prior to its official discovery observation at Tautenburg.

Physical characteristics

According to the survey carried out by NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

with its subsequent

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission, ''Ratzinger'' measures 13.4 kilometers in diameter and its surface has an

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

of 0.09. In 2018, Josef Ďurech ''et al.'' measured its rotation period as hours and provided a partial shape model. As of 2020, ''Ratzinger''s composition remains unknown.

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 ''minor ...

was named after German Joseph Ratzinger (born 1927), then Cardinal and professor of theology, for the role he played in supervising the opening of the Vatican Secret Archives in 1998 to researchers investigating judicial errors against Galileo, after whom the minor planet 697 Galilea is named, and other medieval scientists. Ratzinger was considered to be one of the most authoritative voices in the Vatican and became

in 2005. The name was proposed by the asteroid's first discoverer, Lutz Schmadel. The approved naming citation was published by the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

on 23 May 2000 ().

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Ratzinger 008661 Discoveries by Lutz D. Schmadel Discoveries by Freimut Börngen Named minor planets 8661 Ratzinger 19901014