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Kuiper, the father of modern planetary science

Gerard Kuiper.   | Photo Credit: Gelderen, Hugo van / Anefo/ Wikimedia Commons

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Do you know about the Kuiper Belt in the solar system? A disc-shaped region outside the orbit of Neptune, the Kuiper Belt consists of a lot of icy objects. Apart from being home to plenty of celestial objects and minor planets, the region also produces many comets. It is named after astronomer Gerard Kuiper, who speculated about the existence of such a disc decades before it was actually observed.

Gifted with great eyesight

Born in 1905 in a village in northern Holland, Kuiper was meant to be an astronomer from birth. For he was gifted with eyesight that was the envy of other star gazers. His sharp eyesight meant that he could see some stars with his naked eye that others could only dream of, as these stars were nearly four times fainter than stars that are normally visible to us in the sky. Kuiper had his eyes to the skies from an early age and it was no wonder that he took to astronomy.

He began studying at Leiden University, where the renowned 17th Century Dutch astronomer Christiaan Huygens had also studied, in 1924. The period saw many astronomers flock to the university, meaning Kuiper built friendships with quite a few who went on to make useful contributions to astronomy.

By 1927, Kuiper received his B.Sc. in Astronomy. He finished his doctoral thesis on binary stars in 1933, travelled to the U.S. the same year and became an American citizen in 1937. He started as a fellow at the Lick Observatory in California and went on to work at the Harvard College Observatory, Yerkes Observatory of the University of Chicago, and the University of Arizona.

Kuiper, the father of modern planetary science

Focus on planets


A hard worker who demanded the same kind of devotion and dedication from everyone around him, Kuiper made a number of discoveries that advanced the field of planetary science. Kuiper focussed on planets and objects in the solar system at a time when most astronomers showed little interest in these topics.

In 1947, Kuiper predicted correctly that carbon dioxide is a major component of Mars’ atmosphere. In that same year, he also correctly predicted that the rings of Saturn are composed of ice particles, and discovered Miranda, Uranus’ fifth moon.

In 1949, he discovered Nereid, Neptune’s moon. He also proposed a theory for the origin of the solar system in that year. He suggested that planets had been formed by the condensation of a large cloud of gas around the sun.

Belt that bears his name

It was in 1951 that he proposed the existence of what we now call the Kuiper Belt in an article for the journal Astrophysics. Even though he wasn’t the first to think of the idea (Irish astronomer, engineer and economist Kenneth Edgeworth had proposed the existence of such a disc of bodies), it is Kuiper’s name that is now associated with it.

Kuiper not only used this idea to offer an explanation as to why there were no large planets beyond Neptune, but also suggested that objects from this disc wandered into the solar system as a comet, thereby explaining their origins as well.

Apart from these, Kuiper was also able to prove in 1956 that Mars’ polar ice caps were not made up of carbon dioxide as had been previously believed, but were actually composed of frozen ice. He also predicted in 1964 that our moon’s surface would be “like crunchy snow” to walk on, something that was later verified by U.S. astronaut Neil Armstrong in 1969.

Influential role

Kuiper’s role was influential in the development of infrared airborne astronomy in the 1960s and 1970s. Using these, Kuiper studied the spectroscopy of the sun, stars and planets, something impossible from ground-based observatories.

By the time Kuiper died in 1973, he had left an indelible mark on astronomy. His name, in fact, is now literally on the moon, Mercury and Mars, as craters in these bodies have been named after him. His contributions and discoveries have led many to view him as the father of modern planetary science.

More about Nereid

Nereid, Neptune’s moon, is named after the Nereids, which are sea-nymphs in Greek mythology. It was Kuiper who proposed the name following his discovery on May 1, 1949.

Kuiper made the discovery using a ground-based telescope. It was the last of Neptune’s satellites to be discovered until Voyager 2’s discoveries came about four decades later.

Nereid is among the largest and outermost of Neptune’s known moons with one of the most eccentric orbits for any satellite in our solar system.

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Printable version | Jun 13, 2021 6:25:30 PM |

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