7958 Leakey, provisional designation , is a Hungaria

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

and synchronous

binary system A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter ''(also see animated examples)''. More restrictive definitions require that th ...

from the inner regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

, approximately 3 kilometers in diameter. It was discovered on 5 June 1994, by American astronomer-couple Carolyn and

Eugene Shoemaker Eugene Merle Shoemaker (April 28, 1928 – July 18, 1997) was an American geologist. He co-discovered Comet Shoemaker–Levy 9 with his wife Carolyn S. Shoemaker and David H. Levy. This comet hit Jupiter in July 1994: the impact was televise ...

at the

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

in California, United States. Its

minor-planet moon A minor-planet moon is an astronomical object that orbits a minor planet as its natural satellite. , there are 457 minor planets known or suspected to have moons. Discoveries of minor-planet moons (and binary objects, in general) are importan ...

was discovered in 2012. The asteroid was named after the members of the Leakey family:

Mary Mary may refer to: People * Mary (name), a feminine given name (includes a list of people with the name) Religious contexts * New Testament people named Mary, overview article linking to many of those below * Mary, mother of Jesus, also calle ...

Louis Louis may refer to: * Louis (coin) * Louis (given name), origin and several individuals with this name * Louis (surname) * Louis (singer), Serbian singer * HMS ''Louis'', two ships of the Royal Navy See also Derived or associated terms * Lewis ( ...

and

Richard Richard is a male given name. It originates, via Old French, from Frankish language, Old Frankish and is a Compound (linguistics), compound of the words descending from Proto-Germanic language, Proto-Germanic ''*rīk-'' 'ruler, leader, king' an ...

Orbit and classification

''Leakey'' is a member of the

Hungaria family The Hungaria asteroids, also known as the Hungaria group, are a dynamical group of asteroids in the asteroid belt which orbit the Sun with a semi-major axis (longest radius of an ellipse) between 1.78 and 2.00 astronomical units (AU). They are t ...

, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the

inner Interior may refer to: Arts and media * ''Interior'' (Degas) (also known as ''The Rape''), painting by Edgar Degas * ''Interior'' (play), 1895 play by Belgian playwright Maurice Maeterlinck * ''The Interior'' (novel), by Lisa See * Interior de ...

main-belt at a distance of 1.7–2.0 AU once every 2 years and 7 months (939 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 0.08 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 Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 22 ° 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 again ...

Physical characteristics

''Leakey'' is an assumed

E-type asteroid E-type asteroids are asteroids thought to have enstatite (MgSiO3) achondrite surfaces. They form a large proportion of asteroids inward of the asteroid belt known as Hungaria asteroids, but rapidly become very rare as the asteroid belt proper i ...

Lightcurves

In 2012, and 2015, several

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

s of ''Leakey'' were obtained by astronomers Brian Warner,

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was a leading English actor in the early years of Britain's Royal National Theatre. He was one of the most respected actors of his generation and was at one time regarded as the natur ...

and Daniel Coley. Lightcurve analysis gave a concurring and well-defined

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 2.35 hours with a brightness variation between 0.19 and 0.22

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 ...

().

Diameter and albedo

According to the survey carried out by the

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...

mission of NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...

, ''Leakey'' measures 2.94 kilometers in diameter and its surface has a high

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, 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 ...

of 0.468. The ''Collaborative Asteroid Lightcurve Link '' assumes an albedo of 0.30 – a compromise value between 0.4 and 0.2, corresponding to the Hungaria asteroids both as family and orbital group – and calculates a diameter of 3.35 kilometers based on an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

of 14.3.

Moon

The 2012-photometric lightcurve observation also revealed, that ''Leakey'' is a synchronous

binary asteroid A binary asteroid is a system of two asteroids orbiting their common barycenter. The binary nature of 243 Ida was discovered when the Galileo spacecraft flew by the asteroid in 1993. Since then numerous binary asteroids and several triple a ...

with a

orbiting it every 50.24 hours. The moon (secondary) was designated . It is likely that the secondary body is

tidally locked Tidal locking between a pair of co-orbiting astronomical body, astronomical bodies occurs when one of the objects reaches a state where there is no longer any net change in its rotation rate over the course of a complete orbit. In the case where ...

, which means that its rotation is synchronous with its orbital period. Based on only two observations at the Palmer Divide Observatory (), it is tentatively estimated that the size-ratio of the binary system is , which would give a 1-kilometer diameter for the satellite.

Naming

The minor planet is named after the Leakey's, a family of Kenyan paleoanthropologists:

Mary Leakey Mary Douglas Leakey, FBA (née Nicol, 6 February 1913 – 9 December 1996) was a British paleoanthropologist who discovered the first fossilised ''Proconsul A proconsul was an official of ancient Rome who acted on behalf of a consul. A pro ...

(1913–1996), her husband

Louis Leakey Louis Seymour Bazett Leakey (7 August 1903 – 1 October 1972) was a Kenyan-British palaeoanthropologist and archaeologist whose work was important in demonstrating that humans evolved in Africa, particularly through discoveries made at Olduvai ...

(1903–1972), and their son

Richard Leakey Richard Erskine Frere Leakey (19 December 1944 – 2 January 2022) was a Kenyan paleoanthropologist, conservationist and politician. Leakey held a number of official positions in Kenya, mostly in institutions of archaeology and wildlife conse ...

(born 1944). Working for many years in Tanzania and Kenya, they conclusively proved that human evolution began in Africa rather than Asia. Richard explored the

Koobi Fora Koobi Fora refers primarily to a region around Koobi Fora Ridge, located on the eastern shore of Lake Turkana in the territory of the nomadic Gabbra people. According to the National Museums of Kenya, the name comes from the Gabbra language: ...

archaeological site in Kenya, where many Hominin fossils have been found. 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. Function ...

on 11 April 1998 ().

Orbit and classification

Physical characteristics

Lightcurves

Diameter and albedo

Moon

Naming

Notes

References

External links