Slideshow P8: The history of astronomy

We know that the night skies were studied and constellations of stars were identified over 2400 years ago. From that time, people believed that the Earth was at the centre of the Universe and that everything else in sky revolved round the Earth.

In the early 11th century, the Arab scientist Ibn al-Haytham made observations and calculations and questioned the science of the Earth-centred cosmology.But it was not until the 16th century that a new theory was put forward by Nicolaus Copernicus, a Polish astronomer.

Nicolaus Copernicus (1478–1543)

Copernicus put forward the theory that the Sun was at the centre of the Universe and that all the planets, including the Earth, revolved around the Sun. His idea was not believed by many people at the time and there was no scientific understanding of this motion. So the theory was at first largely ignored.

Galileo Galilei was an Italian scientist, born after the death of Copernicus. He learned about a new invention – the telescope, and he made his own improved version.

Galileo Galilei (1564–1642)

Using his telescope, Galileo discovered the four biggest moons of Jupiter, so supporting the Copernican theory that everything in the sky did not move around the Earth. Although Galileo’s evidence was not believed to be true either!

However, Galileo’s experimental and observational work became the foundation for the modern investigative science and astronomy we have today.Observations and mathematical calculations made by Johannes Kepler in the early 17th century, confirmed the motion of the planets around the Sun.

Isaac Newton was an English scientist and mathematician who supported Galileo’s theory. His laws of motion and concept of gravity provided scientific explanation for the Sun-centred theory and finally established it as correct.

Isaac Newton (1642–1727)

The technology of telescopes has advanced hugely since Galileo’s time.We can now make large telescopes using curved mirrors, and even put them in orbit around the Earth. This avoids the distortion of images that the Earth’s atmosphere produces, so gives us a very clear view of even very distant astronomical objects.

Hubble Space Telescope, launched into orbit in 1990

The technology of spacecraft, computers and robots has allowed us to send remote-controlled rovers to Mars, to explore the surface.

We have sent spacecraft to all parts of the Solar System.The Voyager spacecraft gave us clear, close-up photos of the outer planets.

Voyager spacecraft, launched in 1977, flew by Jupiter in 1979 and is now continuing beyond the edge of the Solar System.

Ground-based telescopes have got larger and larger with advances in technology. These domes house telescopes which can be rotated to view any part of the sky.

Inside its dome, a modern telescope is connected to electronic imaging devices and computers. We can now ‘see’ detail of unimaginably distant galaxies in the Universe.