1. Early man studied the sky by watching every night and noticing where the stars were and how the moon moved. Since then our techniques for exploring space have become very much more sophisticated.

Astronomy

Early astronomers used simple telescopes to look at the stars. They wrote down the positions of the stars and what they could see when they looked through their telescopes. They saw patterns in the sky which helped them to map the sky - they called these patterns constellations and we still use them today.

Modern telescopes use the latest technology to pin point very distant objects. Small telescopes can be bought which can have small computerised locators which you programme to find the star or galaxy you want to see. These can be used in your back garden. These telescopes allow you to see distant galaxies and nebulae and details on the moon which are breathtaking.

Astronomy is one of the only sciences where amateurs can make as big a contribution as professionals and many amateurs have discovered new features and observed comets etc. before professional astronomers.

Dotted around the world, in places where the atmosphere is clear i.e. on the tops of high mountains and there are no towns or cities to cause light pollution, there are giant telescopes. These take the form of huge mirrors which are able to collect the tiniest amounts of light from the far reaches of the galaxy and allow us to see them. You do not look through an eyepiece to use these, but study the images on computers.

The most famous site for this is on Mauna Kea on the island of Hawaii. This is an extinct volcano which is over 4,000 m high. The observatory on the top has huge telescopes which are owned and run by various countries.

The latest are the twin Keck telescopes which can be accessed by scientists all over the world using computer links.

Space Exploration

Scientists can only find out so much by looking through telescopes and for many years we have been sending probes into space carrying special equipment to sample and gather data about the Solar System.

Some of these probes take many years to complete their journeys because of the long distances involved.

Many probes have been sent to fly past the planets and a few have even landed on other planets with varying degrees of success. The Mariner 10 probe passed Mercury; the Viking probes went to Mars and the Venera probe went to The latest probes include the Voyager probes. Voyager 2 has now left the Solar System but is no longer transmitting pictures or information back to Earth. On its trip across the Solar System, it sent us clear pictures of Jupiter, Saturn and the outer planets. It took 12 years to reach Neptune where it showed us 6 new moons and some rings which we had not previously known to exist. (See Teacher’s Note on Space Probes).

The next step has always been to send people into space. Once probes had landed on the Moon, we sent astronauts to explore it and bring back samples and pictures. In the future it is hoped to send men to Mars, but so far we lack the technology and money to undertake the project.

We have been concentrating on the space near to our planet in recent years, first with the space shuttle programme, then the space station Mir and now the International Space Station (ISS) which is being built in orbit. The ISS can be clearly seen travelling overhead at night. It looks like a moving star, travelling quite quickly across the night sky.

It is only visible for a few minutes in any one place per orbit.

To find out when and where to see it in the sky, visit the NASA web page and follow the links to the ISS. You can type in your nearest town and it will tell you when the ISS will next be passing over you. If you are lucky and it coincides with a trip to the ISS by the shuttle you may see the two close together (before docking and on departure) or see the ISS as an even brighter ‘star’.