James Christy & Robert Harrington in 1978

Robert Sutton Harrington (October 21, 1942 – January 23, 1993) was an American

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

who worked at the

United States Naval Observatory United States Naval Observatory (USNO) is a scientific and military facility that produces geopositioning, navigation and timekeeping data for the United States Navy and the United States Department of Defense. Established in 1830 as the Depo ...

(USNO). Harrington was born near

Newport News Newport News () is an independent city in the U.S. state of Virginia. At the 2020 census, the population was 186,247. Located in the Hampton Roads region, it is the 5th most populous city in Virginia and 140th most populous city in the Uni ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

. His father was an

archaeologist Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscap ...

. He was married to Betty-Jean Maycock in 1976, with two daughters, Amy and Ann.Obituary
/ref> Harrington worked at the USNO. Another astronomer there,

James W. Christy James Walter "Jim" Christy (born September 15, 1938) is an American astronomer known for discovering Charon, the largest moon of the dwarf planet Pluto. Early years Christy was born in 1938 in Milwaukee, Wisconsin. He attended the University of ...

, consulted with him after discovering bulges in the images of

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...

, which turned out to be Pluto's

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

Charon In Greek mythology, Charon or Kharon (; grc, Χάρων) is a psychopomp, the ferryman of Hades, the Greek underworld. He carries the souls of those who have been given funeral rites across the rivers Acheron and Styx, which separate the wo ...

. For this reason, some consider Harrington to be a co-discoverer of Charon, although Christy usually gets sole credit. By the laws of

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

, it is easy to determine the

mass Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementar ...

of a binary system based on its orbital period, so Harrington was the first to calculate the mass of the Pluto-Charon system, which was lower than even the lowest previous estimates of Pluto's mass. For much of his career, he proposed the existence of a

Planet X Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and continued at the start of the 20th with Percival Lowell's ...

beyond Pluto and supported searches for it, collaborating initially with T. C. (Tom) Van Flandern. Harrington died of

esophageal cancer Esophageal cancer is cancer arising from the esophagus—the food pipe that runs between the throat and the stomach. Symptoms often include difficulty in swallowing and weight loss. Other symptoms may include pain when swallowing, a hoarse voice ...

in 1993. The

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. ...

3216 Harrington was named in his honour.

Disproof of existence of Planet X

Six months before Harrington's death,

E. Myles Standish Erland Myles Standish Jr. (born March 5, 1939) is a mathematical astronomer largely working in the field of solar system dynamics and celestial mechanics. He is a former professor at Yale University and had worked for the Jet Propulsion Laborato ...

had used data from ''Voyager 2s 1989 flyby of

Neptune Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...

, which had revised the planet's total mass downward by 0.5%—an amount comparable to the mass of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...

Croswell (1997), p. 66.—to recalculate its gravitational effect on

Uranus Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (mythology), Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars (mythology), Mars), grandfather ...

. When Neptune's newly determined mass was used in the Jet Propulsion Laboratory Developmental Ephemeris (JPL DE), the supposed discrepancies in the Uranian orbit, and with them the need for a Planet X, vanished. There are no discrepancies in the trajectories of any space probes such as ''

Pioneer 10 ''Pioneer 10'' (originally designated Pioneer F) is an American space probe, launched in 1972 and weighing , that completed the first mission to the planet Jupiter. Thereafter, ''Pioneer 10'' became the first of five artificial objects to ach ...

'', ''

Pioneer 11 ''Pioneer 11'' (also known as ''Pioneer G'') is a robotic space probe launched by NASA on April 5, 1973, to study the asteroid belt, the environment around Jupiter and Saturn, solar winds, and cosmic rays. It was the first probe to encounter ...

'', ''

Voyager 1 ''Voyager 1'' is a space probe launched by NASA on September 5, 1977, as part of the Voyager program to study the outer Solar System and interstellar space beyond the Sun's heliosphere. Launched 16 days after its twin ''Voyager 2'', ''Voya ...

'', and ''

Voyager 2 ''Voyager 2'' is a space probe launched by NASA on August 20, 1977, to study the outer planets and interstellar space beyond the Sun's heliosphere. As a part of the Voyager program, it was launched 16 days before its twin, ''Voyager 1'', on a ...

'' that can be attributed to the gravitational pull of a large undiscovered object in the outer Solar System. Although most astronomers agree that Planet X, as Lowell defined it, does not exist, as of January 2016 there is speculation concerning

Planet Nine Planet Nine is a hypothetical planet in the outer region of the Solar System. Its gravitational effects could explain the peculiar clustering of orbits for a group of extreme trans-Neptunian objects (ETNOs), bodies beyond Neptune that orbit t ...

References

External links

Obituaries

US Naval Observatory: obituary
{{DEFAULTSORT:Harrington, Robert Sutton 1942 births 1993 deaths American astronomers

Disproof of existence of Planet X

See also

References

External links

Obituaries