Great Astronomers
In the 1600’s, Isaac Newton, an English scientist, worked out the rules for the movement of the stars and the planets. He also realized that the planets move as they do because of the force of gravity between the planets and the sun. In addition, Newton made a new kind of telescope. Instead of using two lenses, he used a curved mirror and a small lens. Most of the huge telescopes used today are based on Newton’s.
William Herschel, who was born in Germany and moved to England, discovered the planet Uranus in 1781. He did so with a telescope he invented. His telescope was 1.2 metres wide, the largest telescope built until 1845. Herschel was also one of the first modern astronomers to study the Milky Way Galaxy.
Friedrich Wilhelm Bessel
In the early 1800’s, German astronomer Friedrich Wilhelm Bessel explained why stars seem to move in the sky.
In the late 1800’s, Annie Jump Cannon, the leading American female astronomer of her time, discovered 300 stars that change their brightness.
Edwin Hubble, an American astronomer, discovered in 1929 that galaxies are moving away from each other at very high speeds.
In the late 1990’s, Stephen Hawking, a British scientist, made important discoveries about gravity, particularly black holes. He also wrote several important books, one of which became very popular.
Helen Sawyer Hogg, an American-born astronomer, began publishing works about ball-like groups of stars that vary in brightness. Sometimes, astronomers use information from Hogg’s discoveries to measure how far certain stars are from Earth.
Picture Credit : Google
