Mountaintop blasted to build huge telescope

The top of a 3,000m-high (10,000ft) mountain in Chile has been blown up to make way for the world's largest optical and infrared telescope.

A million tonnes of rock were blasted in order to create a level surface on which to build the European-Extremely Large Telescope (E-ELT).

At its heart will lie a mirror that is half the size of a football pitch.

Rebecca Morelle reports.