By: Haley Sellers

what to think about

what connections can you see between how the IAU classifies planets, dwarf planets, and, small solar system objects now and in the past?

Discovery of Pluto

Pluto was discovered by Clyde Tombaugh on February 18, 1930. Pluto is part of the Kuiper belt. astronomers thought that their was another planet that was disturbing the orbit of Uranus besides Neptune. Later In 1894 they started a project to find this plant. They were unsuccessful but later Clyde was going through some of their pictures and he found a spot. After he found this spot he looked back and forth between newer and older pictures and discovered Pluto.

Kuiper Belt

the Kuiper belt was discovered in 1992 and is named after the man that discovered it Gerard Kuiper. The Kuiper belt holds a large amount of our solar systems small solar system bodies. Small solar system bodied are objects in the solar system that are not planets, dwarf planets, or satellites. The Kuiper belt contains many different things such as materials that are believed to be left over from the outer planets. When the Kuiper belt was found it changed many things that astronomers thought about. The International astronomical union (IAU) changed many things the year that the Kuiper belt was discovered.

Pluto is Kicked out

Pluto was original the 9th planet in order of distance from the sun and the smallest of the planets. Now because of technological advances Pluto is a dwarf planet. a dwarf planet orbits the sun like other planets but is much smaller. Dwarf planets are so small they can not clear other small solar system objects that are in their path. Pluto is the only dwarf planet to once be thought of as a major planet.

the International Astronomical Union

The international astronomical union (IAU) was created on July 28, 1919. The IAU brings distinguished astronomers from all nations. Their mission it to promote and safeguard the science of astronomy in all its aspects. The IAU is the worlds largest professional body of astronomers.