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, moons, comets and galaxies – in either o ...
and a discoverer of numerous
moons
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...
,
comets
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ...
and
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 '' ...
s in the
outer Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
.
He is an astronomer in the Department of Terrestrial Magnetism at the
Carnegie Institution for Science
The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. T ...
in Washington, DC. He attended Oberlin College as an undergraduate, and received his bachelor in physics with honors in 1998. Starting as a graduate student at the Institute for Astronomy at the
University of Hawaii
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase ''universitas magistrorum et scholarium'', which ...
, he was credited with the discovery of many small moons of
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandt ...
,
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; ...
,
Uranus
Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus (Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of Cronu ...
, and
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 time ...
. He has also discovered the first known trailing
Neptune trojan
Neptune trojans are bodies that orbit the Sun near one of the stable Lagrangian points of Neptune, similar to the trojans of other planets. They therefore have approximately the same orbital period as Neptune and follow roughly the same orbital ...
, , the first named leading Neptune trojan, 385571 Otrera, and the first high inclination Neptune trojan, . These discoveries showed that the Neptune trojan objects are mostly on highly inclined orbits and thus likely captured small bodies from elsewhere in the
Solar System
The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...
.
The
main-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 ...
LONEOS
Lowell Observatory Near-Earth-Object Search (LONEOS) was a project designed to discover asteroids and comets that orbit near the Earth. The project, funded by NASA, was directed by astronomer Ted Bowell of Lowell Observatory in Flagstaff, A ...
at
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 ...
in 1999, was named in his honor.
Discoveries
Sheppard was the lead discoverer of the object with the most distant orbit known in the Solar System, (nicknamed Biden). In 2014, the similarity of the orbit of to other extreme Kuiper belt object orbits led Sheppard and Trujillo to propose that an unknown
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively.
The term "super-Earth" refers only to ...
mass planet (2–15 Earth masses) in the outermost Solar System beyond 200 AU and up to 1500 AU is shepherding these smaller bodies into similar orbits (see
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 ...
or
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 orb ...
). The extreme trans-Neptunian objects and , announced in 2016 and co-discovered by Sheppard, further show a likely unknown massive planet exists beyond a few hundred AU in the Solar System, with being the first known high semi-major axis and high perihelion object anti-aligned with the other known extreme objects. In 2018, the announcement of the high perihelion inner Oort cloud object 541132 Leleākūhonua (nicknamed "The Goblin") by Sheppard et al., being only the third known after and Sedna, further demonstrated that a super-Earth planet in the distant solar system likely exists as Leleākūhonua has many orbital similarities as the two other known inner Oort cloud objects.
Most notable discoveries
Sheppard has been involved in the discovery of many
small Solar System bodies
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, ...
such as
trans-Neptunian object
A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has a semi-major axis of 30.1 astronomical units (au).
Typicall ...
s,
centaurs
A centaur ( ; grc, κένταυρος, kéntauros; ), or occasionally hippocentaur, is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse.
Centaurs are thought of in many Greek myths as bein ...
,
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or Coma (cometary), coma, and sometimes also a Comet ta ...
possible dwarf planets
The number of dwarf planets in the Solar System is unknown. Estimates have run as high as 200 in the Kuiper belt and over 10,000 in the region beyond.
However, consideration of the surprisingly low densities of many large trans-Neptunian objects ...
discovered by Sheppard are 471143 Dziewanna, , , , and .
* In 2018, Sheppard was the lead discoverer of the most distant observed object in our solar system and first object observed beyond 100 AU, dwarf planet (nicknamed Farout), which is around 120 AU from the Sun.
* He discovered a
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 important ...
around likely dwarf planet .
* He is also a co-discoverer of a minor-planet moon orbiting the binary trans-Neptunian object 341520 Mors–Somnus.
* Among the numerous
irregular moon
In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They have been captured by their parent planet, unlike regular ...
s of the major planets in whose discovery he has been involved are:
;Jupiter
Discovered
moons of Jupiter
There are 82 known moons of Jupiter, not counting a number of moonlets likely shed from the inner moons. All together, they form a satellite system which is called the Jovian system. The most massive of the moons are the four Galilean moons: ...
Themisto
In Greek mythology, Themisto (; Ancient Greek: Θεμιστώ) was a Thessalin princess as the daughter of King Hypseus of Lapiths Apollodorus, 1.9.2 and the naiad Chlidanope. Her name is derived from the Ancient Greek word: "θεμιστος" ...
Taygete
In Classical Greek mythology, Taygete el, Ταϋγέτη, , ) was a nymph, one of the Pleiades according to the '' Bibliotheca'' (3.10.1) and a companion of Artemis, in her archaic role as '' potnia theron'', "Mistress of the animals", with its ...
(2000)
*
Kalyke
Kalyke , also known as , is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000, and given the temporary designation .Megaclite
Megaclite , also known as , is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000, and given the temporary designation .Iocaste (2000)
* Dia (2000)
* Euporie (2001)
* Orthosie (2001)
* Euanthe (2001)
* Thyone (2001)
* Hermippe (2001)
* Pasithee (2001)
* Aitne (2001)
*
Eurydome
According to Lucius Annaeus Cornutus' ''Compendium Theologiae Graecae'', Eurydome (Ευρυδόμη; "Structure Outside the Areas") was the mother of the Graces by Zeus
Zeus or , , ; grc, Δῐός, ''Diós'', label=genitive Boeotian ...
Kale
Kale (), or leaf cabbage, belongs to a group of cabbage (''Brassica oleracea'') cultivars grown for their edible leaves, although some are used as ornamentals. Kale plants have green or purple leaves, and the central leaves do not form a head ...
(2001)
*
Arche
''Arche'' (; grc, ἀρχή; sometimes also transcribed as ''arkhé'') is a Greek word with primary senses "beginning", "origin" or "source of action" (: from the beginning, οr : the original argument), and later "first principle" or "element". ...
(2002)
*
Eukelade
Eukelade , also known as , is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003, and received the temporary designation .
Eukelade is about 4 ki ...
(2003)
*
Helike
Helike (; el, , pronounced , modern ) was an ancient Greek polis (city-state) that was submerged by a tsunami in the winter of 373 BC. It was located in the regional unit of Achaea, northern Peloponnesos, two kilometres (12 stadia) from the ...
(2003)
*
Aoede
In Greek mythology, Aoede ( grc, Ἀοιδή, ''Aoidē'') was one of the three original Boeotian muses, which later grew to five before the Nine Olympian Muses were named. Her sisters were Melete and Mneme. She was the muse of voice and song. ...
Mneme
In Greek mythology, Mneme ( grc-gre, Μνήμη, Mnḗmē) was one of the three original Boeotian muses, along with her sisters Aoede and Melete before Arche and Thelxinoë were identified, increasing the number to five. Later, the Nine O ...
Herse
In Greek mythology, Herse ( grc, Ἕρση "dew") may refer to the following figures:
*Herse, daughter of Selene by Zeus, see Ersa.
*Herse, daughter of Cecrops.
*Herse, one of the many consorts of King Danaus of Libya and mother of his daughte ...
S/2003 J 9
is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003.
is about 1 kilometre in diameter, and orbits Jupiter at an average distance of in 767.6 ...
Jupiter LXI
Jupiter LXI, provisionally known as , is a natural satellite of Jupiter. It was discovered by a team of astronomers led by Brett J. Gladman, et al. in 2003.
is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 22,709 ...
Jupiter LXXII
Jupiter LXXII, originally known as , is a natural satellite of Jupiter. It was discovered by Scott Sheppard in 2011. It belongs to the Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar or ...
(2011)
*
Jupiter LVI
Jupiter LVI, provisionally known as , is a natural satellite of Jupiter. It was discovered by Scott Sheppard
Scott Sander Sheppard (born 1977) is an American astronomer and a discoverer of numerous moons, comets and minor planets in the outer Sol ...
Jupiter LIV
Jupiter LIV, originally known as S/2016 J 1, is an outer natural satellite of Jupiter. It was discovered by Scott S. Sheppard in 2016, but not announced until June 2, 2017 via a Minor Planet Electronic Circular from the Minor Planet Center. It i ...
Pandia
In Greek mythology, the goddess Pandia or Pandeia ( grc-gre, Πανδία, Πανδεία, meaning "all brightness") was a daughter of Zeus and the goddess Selene, the Greek personification of the moon. From the ''Homeric Hymn to Selene'', we h ...
(2017)
*
Jupiter LXVI
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but ...
moons of Saturn
The moons of Saturn are numerous and diverse, ranging from tiny moonlets only tens of meters across to enormous Titan, which is larger than the planet Mercury. Saturn has 83 moons with confirmed orbits that are not embedded in its rings—of ...
Bergelmir
Bergelmir ( ; Old Norse: ) is a jötunn in Norse mythology.
Name
The Old Norse name ''Bergelmir'' has been variously translated as 'bear-yeller', 'mountain-yeller', or 'bare-yeller'. According to linguist Jan de Vries, the name should be read ...
(2004)
*
Fenrir
Fenrir ( Old Norse: ; " fen-dweller")Orchard (1997:42). or Fenrisúlfr (O.N.: ; "Fenrir's wolf", often translated "Fenris-wolf"),Simek (2007:81). also referred to as Hróðvitnir (O.N.: ; "fame-wolf")Simek (2007:160). and Vánagandr (O.N.: ...
(2004)
*
Bestla
Bestla (Old Norse: ) is a jötunn in Norse mythology, and the mother of the gods Odin, Vili and Vé (by way of Borr). She is also the sister of an unnamed man who assisted Odin, and the daughter (or granddaughter depending on the source) of the ...
S/2004 S 7
S/2004 S 7 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005 from observations taken between 12 December 2004 and 8 March 2005.
S/2004 S 7 is abou ...
S/2004 S 13
S/2004 S 13 is a natural satellite of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It ha ...
(2004)
*
S/2004 S 17
S/2004 S 17 is a natural satellite of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It ha ...
(2004)
*
Hyrrokkin
Hyrrokkin (Old Norse: ) is a female jötunn in Norse mythology. According to 13th-century poet Snorri Sturluson, she launched the largest of all ships at Baldr's funeral after the Æsir gods were unable to budge the vessel.
Hyrrokkin was a relat ...
S/2006 S 1
S/2006 S 1 is a natural satellite of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has ...
S/2007 S 3
S/2007 S 3 is a natural satellite of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has ...
Gerd Gerd or GERD may refer to:
* Gerd (given name), a list of people with the given name or nickname
* Gerd (moon), a moon of Saturn
* Gerd Island, South Orkney Islands, Antarctica
* Gastroesophageal reflux disease, a chronic symptom of mucosal damage ...
(2019)
*
Saturn LVIII
Saturn LVIII, provisionally known as S/2004 S 26, is the outermost numbered natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, and Jan Kleyna
Jan T. Kleyna is a postdoctoral astronomy researcher at ...
Saturn LXIV
Saturn LXIV, provisionally known as S/2004 S 34, is a natural satellite of Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine ...
moons of Uranus
Uranus, the seventh planet of the Solar System, has 27 known moons, most of which are named after characters that appear in, or are mentioned in, the works of William Shakespeare and Alexander Pope. Uranus's moons are divided into three grou ...
Margaret
Margaret is a female first name, derived via French () and Latin () from grc, μαργαρίτης () meaning "pearl". The Greek is borrowed from Persian.
Margaret has been an English name since the 11th century, and remained popular through ...
(2003)
*
Ferdinand
Ferdinand is a Germanic name composed of the elements "protection", "peace" (PIE "to love, to make peace") or alternatively "journey, travel", Proto-Germanic , abstract noun from root "to fare, travel" (PIE , "to lead, pass over"), and "co ...
(2003), first seen but lost in 2001 by Holman et al.
; Neptune
Discovered
moons of Neptune
The planet Neptune has 14 known moons, which are named for minor water deities in Greek mythology. By far the largest of them is Triton, discovered by William Lassell on October 10, 1846, 17 days after the discovery of Neptune itself; over a ...
Carnegie Institution for Science
The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. T ...