IT is rocket science - at least it is for youngsters taking part in a science event at the University of York.

They will learn how plastic bottles can be transformed into scaled-down versions of intergalactic craft, when all eyes turn to the skies at the university this weekend.

They will get the chance to make their own rockets and launch them skyward as part of a family fun day tomorrow.

The free event is being held to celebrate the centenary of Albert Einstein's Theory of Relativity, which revolutionised our understanding of the universe.

Voyages In Space, as the event has been dubbed, is based on aspects of space linked to Einstein's work on relativity. It is open to the general public, though it is particularly aimed at children over ten.

The demonstrations will include small rockets made from soft drink bottles, powered by water with parachutes attached.

There will also be displays using solid-fuel powered rockets, and rockets that are hydrogen-powered, demonstrating the use of cheap renewable energy.

The event will be held in the university's exhibition centre, in the physics building, from 11am to 4pm.

There will also be a number of activities on the university's sports fields, including displays of rocketry. A large number of demonstrations and exhibits, many of them interactive, will cover aspects of space, space travel and exploration, the position of planets in the solar system, galaxies, black holes, comets and what they are made of, images of the topography of Venus, space probes, and much more.

Organiser Dr David Jenkins said: "We are very excited about having the opportunity to show local children something about our universe and space exploration. We hope to inspire them to follow in the footsteps of famous scientists like Einstein and be the astronomers and physicists of the future."

Updated: 10:47 Friday, September 02, 2005