Media playback is unsupported on your device

Giant telescope to study star secrets

12 June 2012 Last updated at 14:05 BST

Construction of world's biggest optical telescope has been approved by member states of the European Southern Observatory (Eso).

The European Extremely Large Telescope (E-ELT) will have a primary mirror some 40m in diameter, and will be built on top of a mountain in Chile.

Pallab Ghosh reports.