Is NASA’s James Webb Space Telescope a Time Machine?

20 May 2011

An artist's picture of what the James Webb Space Telescope will look like in orbit

This is the VOA Special English Technology Report.

If you could build a time machine, what would it look like? Maybe, it should look like a telescope. American scientists are building a space telescope, they hope, will look back over unimaginable distances and time to show the universe close to its beginning.

But this distant past will mainly be seen in infrared light. Visible light is just one form of radiation. Today, telescopes take pictures using forms of light hidden from the human eye.

The American space agency, NASA, is now building the largest space telescope ever. The James Webb Space Telescope, named after NASA’s second director, will have a mirror seven times the size of the Hubble Space Telescope.

But it will mainly study the universe in infrared light. We usually experience infrared light as heat. But, if you have ever used a TV remote control, you know there are many uses for it.

The James Webb Space Telescope is a complex engineering project. It will be huge -- about the size of a passenger jet. And it will have to be super-cooled. Because the telescope studies infrared heat, its mirror must be kept very close to absolute zero. That is minus two hundred seventy-three degrees Celsius.

NASA is building the Webb telescope at the Goddard Space Center, outside Washington DC. The agency hopes to launch it in twenty-fourteen.