The world's largest telescope starts using its complex structure of mirrors today to scour the outer reaches of the universe for planets similar to our own and to seek clues to help explain the origins of life.

Set on a mountain on an Atlantic island, far enough from human habitation to get a clear view of the night sky, the Great Canary Telescope carries with it the hopes of scientists who believe clues to understanding our world can be found in as yet unseen parts of the universe. The telescope will, in effect, peer back in time as it picks up light emitted long ago in other parts of the universe.

A powerful array of 36 separate mirrors form a single mirror that is 10.4 metres (34ft) wide, 4% larger than the Keck telescopes at Mauna Kea, Hawaii. The GTC's powerful eye will penetrate dense, cold molecular "clouds" to watch stars being born and will seek out the most distant galaxies and quasars.

"The GTC will be able to see the weakest and most distant celestial objects in the universe," said a spokesman for the telescope's owners, who include the Spanish government and the regional government of the Canary Islands. "It will be able to capture the birth of new stars, study in greater depth the characteristics of black holes and decipher the chemical compounds that appeared after the Big Bang. One of its most emblematic objectives is to find planets similar to our own in other stellar systems."

The telescope is set on a peak 2,400 metres above the Canary island of La Palma, sitting on a "sea of clouds", with the skies above it kept clear by the Atlantic trade winds. Although battered by winds and, on occasions, snow and ice, the peak, known as the Roque de Los Muchachos, is one of the best spots for gazing at the night sky. The quality of the skies above the Canary Islands is protected, and has drawn 62 astronomy institutes to the islands.

Construction of the €130m (£88m) telescope has taken seven years, hampered by poor weather and the fact that each delicately engineered piece has to be driven up a winding road to the peak. The GTC will stand on its own, bucking a trend for building telescopes in groups to multiply viewing strength.

"The GTC will be the biggest telescope in the world," said the project manager, Pedro Alvarez. "It will observe things that are so small, or so very far off, that only a small amount of light reaches us. It will also see closer objects that either do not emit their own light or emit very little light. You need the biggest possible light-collecting surface to be able to see them."

A steel protective shell and "indestructible" concrete bunker protect the new telescope from the elements.