WhoAwee.com - Free Online Famous Astronomical Discoveries for Kids

Neptune was discovered by John Couch Adams in 1846. Adams was an English astronomer and mathematician who, at the age of 24, was the first person to predict the position of a planetary mass beyond Uranus.

Discovery of Pluto

Pluto was discovered by astronomer Clyde Tombaugh in 1930. A 9th planet had been looked for some time. It was believed that such a planet had to exist in order to explain some odd things happening in the orbits of Uranus and Neptune. Only 3 of the 9 planets in our solar system have official "discoverers" and "times of discovery." The reason is simple - all of the other planets are easily seen by the unaided human eye. This means that humankind has been looking at these objects (whether they understood what they were or not) since first gazing at the night sky!

Discovery of Uranus

Uranus was discovered by Sir William Herschel in 1781. Herschel was probably the most famous astronomer of the 18th century. In addition to discovering the planet Uranus, he also observed and cataloged over 800 double stars and 2,500 nebulae. He was the first astronomer to correctly describe the spiral structure of our Milky Way Galaxy.

General Relativity(1915 – 1919)

General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1915.

Halley's Comet Has a Predictable Orbit(1705 – 1758)

Edmund Halley proves that comets orbit the sun like the planets and successfully predicts the return of Halley's Comet. He determines that comets seen in 1531 and 1607 are the same object following a 76-year orbit. Halley's prediction is proven in 1758 when the comet returns. Unfortunately, Halley had died in 1742, missing the momentous event.

Planetary Orbits Are Elliptical(1605 – 1609)

Johannes Kepler devises mathematical laws that successfully and accurately predict the motions of the planets in elliptical orbits.

The Earth Moves (1543)

Nicolaus Copernicus places the sun, not the Earth, at the center of the solar system.

The Milky Way Is a Gigantic Disk of Stars(1780 – 1834)

Telescope-maker William Herschel and his sister Carolyn map the entire sky and prove that our solar system resides in a gigantic disk of stars that bulges in the center called the Milky Way.

The Planets Move (2000 B.C. – 500 B.C.)

A thousand years of observations reveal that there are stars that move in the sky and follow patterns, showing that the Earth is part of a solar system of planets separate from the fixed stars.

The Universe Is Expanding (1924 – 1929)

Edwin Hubble determines the distance to many nearby galaxies and discovers that the farther they are from us, the faster they are flying away from us. His calculations prove that the universe is expanding.

The Center of the Milky Way Emits Radio Waves (1932)

Karl Jansky invents radio astronomy and discovers a strange radio-emitting object at the center of the Milky Way

Cosmic Microwave Background Radiation (1964)

Arno Penzias and Robert Wilson discover cosmic microwave background radiation, which they suspect is the afterglow of the big bang..

Gamma-Ray Bursts (1969 – 1997)

The two-decade-long mystery of gamma-ray bursts is solved by a host of sophisticated ground-based and orbiting telescopes.

Planets Around Other Stars (1995 – 2004)

Astronomers find a host of extra solar planets as a result of improved telescope technology and prove that other solar systems exist, although none as yet resembles our own. Astronomers are able to detect extra solar planets by measuring gravitational influences on stars.

The Universe Is Accelerating (1998 – 2000)

Unexpectedly, astronomers find that instead of slowing down due to the pull of gravity, the expansion of the universe at great distances is accelerating. If these observations are correct and the trend continues, it will result in the inability to see other galaxies. A new theory of the end of the universe based on this finding has been called the "big rip."