Looking into space P1b 7.3 What can we see in space?  NASA SLIDE 1

The first astronomical observatory? Stonehenge was probably used to allow very accurate sightings of the position of the Sun and Moon at particular times of the year. Exactly why ancient Britons needed to do this we don’t know but presumably it was quite important – those big rocks were transported hundreds of miles from West Wales to do the job! SLIDE 2

The Greeks and Romans also made a lot of effort to plot the positions of the stars. Many of the constellations we know today have names based on Roman ideas. Like the ancient Britons the Romans did not have telescopes because they did not have lenses.  Stephan Gustafson SLIDE 3

Although he was not the first person to use an astronomical telescope, Galileo was the person who really made the instrument famous. He looked up at the night sky and saw that the Moon's surface was covered with pits and craters. He saw moons orbiting around Jupiter and the rings around Saturn. Galileo realised that his observations supported the idea that the Sun is the centre of the Solar System not the Earth. The Catholic Church regarded a Sun- centred Solar System as heresy and Galileo was placed under house arrest for publishing his ideas – although he escaped being executed, which was the standard treatment for heretics in those days! SLIDE 4

The next big step forward came from Sir Isaac Newton. He developed a completely new design of telescope that used a curved mirror rather than a lens. This telescope was only 15 cm long, but it could magnify more than a telescope nearly 2 metres long using lenses alone. Newton was a strange mixture. He was a rational scientist and at the same time worked on alchemy, looking for a way to produce a medicine that would give him eternal life and a way to change ordinary metal into gold. SLIDE 5

After Isaac Newton telescopes became bigger and more complex, allowing astronomers to see further and further into space. But they all followed the same basic pattern using mirrors or lenses to magnify images from the skies. In 1945 the next step came with the setting up of a ‘radio telescope’ at Jodrell Bank near Manchester. The astronomer was Dr Bernard Lovell and he soon realised that radio waves could be used to tell us about the stars in the same way as visible light.  Jedrell Observatory SLIDE 6

com/science/extreme_machine s/ html The world’s largest radio telescope now consists of an array of smaller telescopes linked together by a supercomputer. Small ‘telescopes’ spread across Holland and Germany work together to produce a radio telescope with a dish measuring 188 miles across! It is based in Holland and can look at radio signals coming in from anywhere in the sky. When it is fully operational the astronomers hope to be able to detect radio waves coming from objects right at the very edge of the universe!  Astron Nico Vermaas SLIDE 7

But optical telescopes which use light are still useful. The Hubble Telescope is actually a satellite orbiting the Earth. Above the atmosphere its optical telescopes get a very good view of deep space. Hubble has produced some of the most amazing photographs of stars and galaxies ever seen. SLIDE 8

An image of the Horsehead Nebula taken by The Hubble Telescope  Digital Vision 9 (NT) SLIDE 9