In 1609, using this early version of the telescope, Galileo became the first person to record observations of the sky made with the help of a telescope. He soon made his first astronomical discovery.
Galileo was the first to point a telescope skyward. He was able to make out mountains and craters on the moon, as well as a ribbon of diffuse light arching across the sky — the Milky Way. He also discovered the rings of Saturn, sunspots and four of Jupiter’s moons.
Galileo wrote a book “Dialogue Concerning the Two Chief World Systems, Ptolemaic and Copernican” and dedicated it to the Pope Urban VIII. But his ideas were considered heretical, and Galileo was called to appear before the inquisition in Rome in 1633. He struck a plea bargain and was sentenced to house arrest, where he continued to work and write until his death in 1642.
Elsewhere in Europe, scientists began improving the telescope. Johannes Kepler studied the optics and designed a telescope with two convex lenses, which made the images appear upside down. Working from Kepler’s writings, Isaac Newton reasoned it was better to make a telescope out of mirrors rather than lenses and built a reflecting telescope in 1668. Centuries later the reflecting telescope would dominate astronomy.
Picture Credit : Google
