2709 Sagan, provisional designation , is a stony Florian asteroid 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, c ...

, approximately 6.7 kilometers in diameter. It was discovered on 21 March 1982, by American astronomer

Edward Bowell Edward L. G. "Ted" Bowell (born 1943 in London), is an American astronomer. Bowell was educated at Emanuel School London, University College, London, and the University of Paris. He was principal investigator of the Lowell Observatory Near-Earth ...

at Lowell's

Anderson Mesa Station Anderson Mesa Station is an astronomical observatory established in 1959 as a dark-sky observing site for Lowell Observatory. It is located at Anderson Mesa in Coconino County, Arizona, about 12 miles southeast of Lowell's main campus on Mars H ...

near Flagstaff, Arizona, and named after astronomer and science popularizer Carl Sagan.

Orbit and classification

''Sagan'' is a member of the

Flora family The Flora family (''adj. Florian''; ; also known as ''Ariadne family'') is a prominent family of stony asteroids located in the inner region of the asteroid belt. It is one of the largest families with more than 13,000 known members, or approxi ...

, one of the largest families of stony asteroids. It orbits the Sun in the inner main-belt at a distance of 2.0–2.3 AU once every 3 years and 3 months (1,188 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 0.07 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 3 ° 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 ...

Physical characteristics

In the

SMASS 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 differentiat ...

, ''Sagan'' is classified as a

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 ...

. It has 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 0.26, according to observations made by the

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 201 ...

and subsequent

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 201 ...

mission. The body has a rotation period between 5.254 and 5.258 hours and a brightness variation between 0.09 and 0.63

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 ...

().

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 ...

was named in honor of Carl Sagan (1934–1996), planetary scientist at

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...

, science popularizer, editor of the journal '' Icarus'', and founder of

The Planetary Society The Planetary Society is an American internationally-active non-governmental nonprofit organization. It is involved in research, public outreach, and political space advocacy for engineering projects related to astronomy, planetary science, a ...

. Sagan participated on a number of planetary space missions, including the Voyager mission to the outer planets and the Mariner 9 and

Viking program The ''Viking'' program consisted of a pair of identical American space probes, ''Viking 1'' and ''Viking 2'', which landed on Mars in 1976. Each spacecraft was composed of two main parts: an orbiter designed to photograph the surface of Mars f ...

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

. Sagan's research encompassed studies of the greenhouse effect on

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

, the atmosphere and surface of Titan, windblown dust on Mars, and the possibility of extraterrestrial intelligent life. Sagan won the Pulitzer Prize for literature in 1978. The official naming citation was published by the Minor Planet Center on 4 August 1982 (). An asteroid discovered in 1998, 4970 Druyan, is named after Sagan's wife

Ann Druyan Ann Druyan ( ; born June 13, 1949) is an Emmy and Peabody Award-winning American documentary producer and director specializing in the communication of science. She co-wrote the 1980 PBS documentary series ''Cosmos'', hosted by Carl Sagan, ...

and is said to be in a "wedding ring orbit" with respect to 2709 Sagan.

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

) * Schmadel, Lutz D.
Dictionary of Minor Planet Names
Google books * Behrend, Raoul
Asteroids and comets rotation curves, CdR
– Observatoire de Genève

– Minor Planet Center * * {{DEFAULTSORT:Sagan 002709 Discoveries by Edward L. G. Bowell Named minor planets 2709 Sagan 002709 19820321