Harold James Reitsema is an American astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

 who was part of the teams that discovered Larissa

Larissa (moon)

Larissa , also known as Neptune VII, is the fifth-closest inner satellite of Neptune. It is named after Larissa, a lover of Poseidon in Greek mythology and eponymous nymph of the city in Thessaly.- Discovery :...

, the fifth of Neptune

Neptune

Neptune is the eighth and farthest planet from the Sun in the Solar System. Named for the Roman god of the sea, it is the fourth-largest planet by diameter and the third largest by mass. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times...

's known moons

Natural satellite

A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....

, and Telesto

Telesto (moon)

Telesto is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated '. In the following months, several other apparitions were observed: , , and ....

, Saturn

Saturn

Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...

's thirteenth moon. Reitsema and his colleagues discovered the moons through ground-based telescopic observations. Using a coronagraphic imaging system with one of the first charge-coupled devices available for astronomical use, they first observed Telesto on April 8, 1980, just two months after being one of the first groups to observe Janus

Janus (moon)

Janus is an inner satellite of Saturn. It is also known as Saturn X . It is named after the mythological Janus.-Discovery and orbit:Janus occupies practically the same orbit as the moon Epimetheus...

, also a moon of Saturn. Reitsema, as part of a different team of astronomers, observed Larissa on May 24, 1981, by watching the occultation of a star by the Neptune system.

Reitsema is also responsible for several advances in the use of false-color

False-color

A false-color image is an image that depicts a subject in colors that differ from those a full-color photograph would show.-True- and false-color:...

 techniques as applied to astronomical images. He was a member of the Halley Multicolour Camera team on the ESA

European Space Agency

The European Space Agency , established in 1975, is an intergovernmental organisation dedicated to the exploration of space, currently with 18 member states...

 Giotto

Giotto mission

Giotto was a European robotic spacecraft mission from the European Space Agency, intended to fly by and study Halley's Comet. On 13 March 1986, the mission succeeded in approaching Halley's nucleus at a distance of 596 kilometers....

 spacecraft that took close-up images of Comet Halley

Comet Halley

Halley's Comet or Comet Halley is the best-known of the short-period comets, and is visible from Earth every 75 to 76 years. Halley is the only short-period comet that is clearly visible to the naked eye from Earth, and thus the only naked-eye comet that might appear twice in a human lifetime...

 in 1986.

Reitsema received a B.A. in Physics from Calvin College

Calvin College

Calvin College is a comprehensive liberal arts college located in Grand Rapids, Michigan. Founded in 1876, Calvin College is an educational institution of the Christian Reformed Church and stands in the Reformed tradition of Protestantism...

 in Grand Rapids, MI in 1970 and a Ph.D. in Astronomy from NMSU

New Mexico State University

New Mexico State University at Las Cruces , is a major land-grant university in Las Cruces, New Mexico, United States...

 in 1977. His dissertation was titled "Quantatative Spectral Classification of Solar-Type Stars and the Sun" with advisor Reta Beebe

Reta Beebe

Reta F. Beebe is an American astronomer, author, and popularizer of astronomy. She is an expert on the planets Jupiter and Saturn, and the author of Jupiter: The Giant Planet...

. He has been involved in many of NASA's space science missions including the Spitzer Space Telescope

Spitzer Space Telescope

The Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...

, Submillimeter Wave Astronomy Satellite

Submillimeter Wave Astronomy Satellite

The Submillimeter Wave Astronomy Satellite was an astronomical observatory launched on December 5, 1998 as part of the Small Explorer program within NASA...

, the New Horizons mission to Pluto

Pluto

Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...

 and the Kepler Space Observatory project searching for Earth-like planets orbiting distant stars similar to the Sun.

Reitsema participated in the ground-based observations of Deep Impact mission in 2005. He observed the impact on the Tempel 1 comet from the telescopes of the San Pedro Martir Observatory (Mexico) with Kevin Walsh (U. Maryland), Ashley Zauderer (U. Maryland) and Roberto Vazquez(UNAM

Unam

UNAM or UNaM may refer to:* National University of Misiones, a National University in Posadas, Argentina*National Autonomous University of Mexico , the large public autonomous university based in Mexico City...

).

Reitsema retired in 2008 from Ball Aerospace & Technologies Corp. in Boulder, Colorado

Boulder, Colorado

Boulder is the county seat and most populous city of Boulder County and the 11th most populous city in the U.S. state of Colorado. Boulder is located at the base of the foothills of the Rocky Mountains at an elevation of...

. He is a consultant to NASA and the aerospace industry in mission design and Near-Earth Objects. He is listed in Who's Who in America. Main-belt

Asteroid belt

The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...

 asteroid

Asteroid

Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

 13327 Reitsema was named in recognition of his achievements.