For years, we have been directing glances, telescopes and microphones at the darkness of the universe. But is there really life out there? Right now, work is underway on the Giant Magellan Telescope, which will become one of the world's largest optical telescopes.

Some scientists believe that signs of life can appear in the form of gases in planetary atmospheres, so-called biosignatures. Gases react differently to light and therefore an optical telescope can help scientists understand which gases are on other planets.

A researcher investigating biosignatures is Sara Seager, professor of planetology at MIT.

- We had all loved finding an alien, but will be happy no matter what signs we find. Each gas has its own way of interacting with light and we hope with new telescopes to be able to find gases that can help us predict if there can be life in other places, she says in a report sent in the Science world.

Hard to detect

About 2.5 billion years ago, living organisms on earth began to pump out a powerful biosignature, oxygen. Now our atmosphere consists of about 20 percent oxygen, which in our measurements is a sure sign of life.

"Biosignatures are puzzle pieces, but the puzzle will be incomplete until we find oxygen," says Mercedes López-Morales, astrophysicist at Harvard University, in the world of science.

But oxygen is a biosignature with a very weak signal and it can therefore be difficult to detect, even for NASA's most powerful space telescope James Webb, which is scheduled to be broadcast in 2021. So work on detecting biosignatures is also taking place at ground level.

New era in the search

Researchers are currently turning seven huge slabs of glass into giant mirrors. Each of the mirrors will weigh 20 tons and be assembled into a single giant mirror on a mountain in Chile.

Just like this, the telescope is supposed to look.

The telescope is expected to have ten times higher resolution than the Hubble Space Telescope, which was of great importance to astronomical science. The new telescope is scheduled to start looking for oxygen on other planets in ten years.

- Giant Magellan Telescope will take us into a new era in the search for life, says Mercedes López-Morales.

See more about the researchers' search for life in the universe in the World of Science, which will be broadcast on Monday, November 26 at 8pm in SVT2 or on SVT Play.