Harold James Reitsema (born January 19, 1948)
is 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 was part of the teams that discovered
Larissa
Larissa (; el, Λάρισα, , ) is the capital and largest city of the Thessaly region in Greece. It is the fifth-most populous city in Greece with a population of 144,651 according to the 2011 census. It is also capital of the Larissa regiona ...
, the fifth of
Neptune's known moons, and
Telesto,
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
In ancient Roman religion and myth, Janus ( ; la, Ianvs ) is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. He is usually depicted as having two faces. The month of January is named for Janu ...
, 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 (or pseudo color) refers to a group of color rendering methods used to display images in color which were recorded in the visible or non-visible parts of the electromagnetic spectrum. A false-color image is an image that depicts ...
techniques as applied to astronomical images. He was a member of the Halley Multicolour Camera team on the
ESA
, owners =
, headquarters = Paris, Île-de-France, France
, coordinates =
, spaceport = Guiana Space Centre
, seal = File:ESA emblem seal.png
, seal_size = 130px
, image = Views in the Main Control Room (1205 ...
Giotto
Giotto di Bondone (; – January 8, 1337), known mononymously as Giotto ( , ) and Latinised as Giottus, was an Italian painter and architect from Florence during the Late Middle Ages. He worked during the Gothic/Proto-Renaissance period. Giot ...
spacecraft that took close-up images of
Comet Halley
Halley's Comet or Comet Halley, officially designated 1P/Halley, is a List of periodic comets, short-period comet visible from Earth every 75–79 years. Halley is the only known short-period comet that is regularly visible to the naked eye fr ...
in 1986.
Reitsema received a B.A. in physics from
Calvin College
Calvin University, formerly Calvin College, is a private Christian university in Grand Rapids, Michigan. Founded in 1876, Calvin University is an educational institution of the Christian Reformed Church and stands in the Reformed (Calvinist) ...
in
Grand Rapids, Michigan
Grand Rapids is a city and county seat of Kent County, Michigan, Kent County in the U.S. state of Michigan. At the 2020 United States census, 2020 census, the city had a population of 198,917 which ranks it as the List of municipalities in Mi ...
in 1972 and a Ph.D. in astronomy from
New Mexico State University in 1977. His dissertation was titled "Quantitative Spectral Classification of Solar-Type Stars and the Sun" with advisor
Reta Beebe. He has been involved in many of
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research.
NASA was established in 1958, succeeding t ...
's space science missions including the
Spitzer Space Telescope
The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...
,
Submillimeter Wave Astronomy Satellite
Submillimeter Wave Astronomy Satellite (SWAS, also Explorer 74 and SMEX-3) is a NASA submillimetre astronomy satellite, and is the fourth spacecraft in the Small Explorer program (SMEX). It was launched on 6 December 1998, at 00:57:54 UTC, fro ...
, the
New Horizons mission to
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 ...
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
The National Autonomous University of Mexico ( es, Universidad Nacional Autónoma de México, UNAM) is a public research university in Mexico. It is consistently ranked as one of the best universities in Latin America, where it's also the bigges ...
).
(Deep Impact observations from San Pedro Martir)
/ref>
Reitsema retired in 2008 from Ball Aerospace & Technologies Corp. in Boulder, Colorado
Boulder is a home rule city that is the county seat and most populous municipality of Boulder County, Colorado, United States. The city population was 108,250 at the 2020 United States census, making it the 12th most populous city in Color ...
. He is a consultant to NASA and the aerospace industry in mission design and Near-Earth Objects
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
. He is the Mission Director for the B612 Foundation's Sentinel program
Sentinel was a proposed US Army anti-ballistic missile (ABM) system designed to provide a light layer of protection over the entire United States, able to defend against small ICBM strikes like those expected from China, or accidental launches f ...
that will find Near Earth Asteroids and identify potential Earth impact threats. He is listed in '' Who's Who in America''. Asteroid 13327 Reitsema was named in recognition of his achievements.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 24 July 2002 ().
References
{{DEFAULTSORT:Reitsema, Harold J.
Living people
American astronomers
1948 births