Discovering All About Gerard Kuiper

Discovering All About Gerard Kuiper
Page content

Brief Biography

Gerard Kuiper was born in a small village in the Netherlands in 1905. He was fascinated by astronomy from a very early age, a fact that led him to study astronomy at the University of Leiden. At the time, the department was bursting with renowned scientists and students of great potential that later became well-known in their fields. Some famous names are Jan Oort, Paul Ehrenfest and Kuiper’s doctoral supervisor Ejnar Hertzsprung.

He received his B.Sc. in Astronomy in 1927 and after completing his doctoral dissertation on binary stars in 1933, he moved to California to become a fellow under R. G. Aitken at the Lick Observatory. In 1935, he was already working for the Harvard College Observatory, when he met Sarah Fuller, his future wife. The couple was married on June 20, 1936. A year later in 1937, he obtained American citizenship.

Kuiper also worked at the Yerkes Observatory of the University of Chicago and at the University of Arizona where he established the Lunar and Planetary Laboratory of the astronomy department. During the 1960’s, he was the chief scientist for the Ranger lunar probe program in which he helped to identify landing sites for the Surveyor and Apollo Programs on the Moon.

Discoveries and Other Contributions

Kuiper is well-known for a series of discoveries in the planetary field. The most important are listed below in a chronological order:

A Simulation of Saturn Rings as Seen from a Position High in the Atmosphere of the Planet. Four Moons are Also Visible: Titan, Dione, Prometheus and Pallene

  • 1944: He proved the existence of an atmosphere around the largest moon of Saturn, Titan.

  • 1947: He discovered that Mars’ atmosphere mostly consists of carbon dioxide (95.32%), verified the existence of Miranda, the fifth and most distant moon of Uranus and also confirmed the fact that the rings of Saturn are made almost entirely of water ice, with smaller percentages of dust and other chemicals.

  • 1949: He proposed that the planets of our Solar System were formed by the condensation of enormous gas and dust clouds orbiting the Sun, a theory that is still the most widely accepted today. He also discovered the existence of Nereid, one of the outermost of Neptune’s known moons.

  • 1951: He discovered the source of short-term comets, a region outside the orbit of Neptune consisting of minor planets and asteroids. This is known today as the Kuiper Belt.

    A Color Composite Picture of Miranda Taken by Voyager 2 in 1986 from a Distance of 147,000 km

  • 1956: He studied the polar icecaps of Mars and confirmed the fact that they’ re composed of frozen water instead of carbon dioxide as it was previously believed.

  • 1964: He accurately described the feeling astronauts would get when walking on the Moon - “like crunchy snow”, a fact that was later verified by astronaut Neil Armstrong.

Apart from his major discoveries in planetary science, Gerard is also known for his contribution in stellar astronomy; he studied white dwarfs, double star systems and high-proper-motion stars. He also used a technique called infrared spectroscopy to study the celestial bodies that interested him. In order to perform his infrared observations he used an onboard telescope of a Convair 990 aircraft in 1967 (40,000 feet altitude) and made many fascinating discoveries. It is no wonder that he is regarded by many as the father of modern planetary science.

Honors and Recognition

  • A minor planet “1776 Kuiper” and craters on Mercury, Mars and the Moon were named after him (“Kuiper Craters”).
  • In order to honor him for his contributions in the development of infrared astronomy, in 1975 NASA named the telescope onboard the Lockheed C141 StarLifter aircraft the “Kuiper Airborne Observatory”.
  • He helped identify several binary stars, which received Kuiper numbers such as Kui 79.
  • In 1959, he won the Henry Norris Russell Lectureship of the American Astronomical Society.
  • In 1984, the American Astronomical Society Division of Planetary Sciences established the Kuiper Prize in order to honor the great scientist. The award is given annually as a recognition for the contribution of distinguished planetary scientists

Interesting Facts and Personal Traits

  • Interestingly, Kuiper was the son of a tailor.
  • He had very sharp eyesight and could see magnitude 7.5 stars with the naked eye. For comparison, this is four times fainter than visible to normal eyesight.
  • He was one of the first scientists to focus almost exclusively on studying the properties of planets.
  • The New Horizons mission will reach the Kuiper Belt in about 2073, about one hundred years after Gerard’s death.

According to scientist D. Cruikshank, Kuiper was a highly perceptible, hard working individual who dedicated his life to his passion for research. He demanded the same degree of devotion from his surrounding environment including his students, colleagues and associates. Despite his serious and reserved nature, he also had a friendly and humorous side and showed a natural curiosity and interest for a variety of topics and activities. Kuiper passed away from a heart attack at the age of 68, while on vacation with his wife in Mexico in 1973.


  • ‘Gerard Kuiper’ by NASA
  • The New Netherland Institute,
  • D.P.Cruikshank, “Gerard Peter Kuiper”, National Academy of Sciences, 1993

Image Credits:

  • “The Famous Astronomer Gerard Kuiper”, (Wikimedia Commons)
  • “A Simulation of Saturn Rings as Seen from a Position High in the Atmosphere of the Planet. Four Moons are Also Visible: Titan, Dione, Prometheus and Pallene”, by the Singing Badger (Wikimedia Commons)
  • “A Color Composite Picture of Miranda Taken by Voyager 2 in 1986 from a Distance of 147,000 km” , NASA/JPL