Large Zenith Telescope facts for kids
The Large Zenith Telescope (LZT) is a very large telescope with a mirror that is 6.0 metres wide. It is located in the University of British Columbia's Malcolm Knapp Research Forest. This forest is about 70 kilometers (43 miles) east of Vancouver, Canada. The LZT is known as one of the biggest telescopes in the world.
What is a Zenith Telescope?
A special type of telescope is called a zenith telescope. It can only point straight up into the sky. This design allows it to use a unique kind of mirror. Instead of a solid piece of glass, it uses a smoothly spinning pan filled with liquid mercury.
How the Mirror Works
The LZT uses about 28 liters (7.4 US gallons) of mercury for its mirror. This mercury spins around once every 8.5 seconds. When a liquid spins, its surface naturally forms a perfect bowl shape. This shape is ideal for focusing light, just like a regular telescope mirror. Liquid mirrors can be made much larger and are cheaper than traditional glass mirrors. This means they can collect a lot more light from distant stars and galaxies.
Seeing the Stars
The light collected by the mercury mirror is focused onto a CCD. A CCD is like the sensor in a digital camera. It turns the light into an image. The LZT uses a method called "transit imaging." Because the telescope only looks straight up, the Earth's rotation causes stars to slowly move across its view. The telescope's sensor moves electronically at the same speed as the stars. This allows it to take clear pictures as the stars pass by.
Building the Telescope
The Large Zenith Telescope was built in 1994. It was put together using parts from another telescope. These parts came from the three-meter wide NASA Orbital Debris Observatory telescope. That telescope had been used for several years before it was taken apart a couple of years earlier.
