World′s largest radio telescope set to start | Science | In-depth reporting on science and technology | DW | 12.03.2013

Visit the new DW website

Take a look at the beta version of We're not done yet! Your opinion can help us make it better.

  1. Inhalt
  2. Navigation
  3. Weitere Inhalte
  4. Metanavigation
  5. Suche
  6. Choose from 30 Languages


World's largest radio telescope set to start

ALMA - the largest and most expensive radio telescope on Earth - goes into operation on Wednesday. It could help answer questions about the formation of the universe and how it will change.

Like trees poking out of the ground, 66 state-of-the-art radio telescopes stand high in Chile's Atacama Desert. They are part of the system that forms the world's largest radio telescope, ALMA.

ALMA is short for Atacama Large Millimeter/sub-millimeter Array.

The super telescope is slated to go into full operation on Wednesday (13.03.2013) after at least 10 years of preparations.

It was designed to withstand difficult conditions and is located about 5,000 meters above sea level in one of the driest places in the world, where temperature differences of up to 50 degrees Celsius and strong winds make it difficult to build anything.

The project has now become the world's largest and most expensive astronomical project - costing more than 1 billion euros.

But scientists say it's worth it.

"It's comparable to the transition from the naked eye to the first telescope," says Wolfgang Wild, ALMA's European Project Manager.

The image shows the radio telescope in the desert

The conditions in the Atacama Desert made it difficult to build the telescope

The individual radio telescopes, or antennae, that form the array are the most advanced that have ever been made. They can receive electromagnetic radiation at wavelengths in the submillimeter range. When connected as one, they are like a huge eye - 16 kilometers in diameter.

"The connection of several antennae means a huge increase in performance," says Wild. Astronomers want to use the images that will be captured by the telescope to unravel one of the biggest secrets - how the universe was formed.

The Big Bang

Nature - as we know it - was created in one of the most unimaginable and strangest developments.

It is hard to believe that the diversity of our landscapes and environments is based on around a hundred different chemical elements. But they are.

And it's all part of the cosmic cycle of life and death.

Think of a star.

Light elements, such carbon, are formed at the core of a star. Metals, such as gold and titanium, are created when that star explodes. And when the star explodes, it distributes the outer shell and elements that are formed during its life cycle.

The shells go towards the creation of clouds - and they in turn produce new stars.

But the question is how this life cycle began.

Using ALMA, astronomers want to target the first star, which began this cosmic process more than 13 billion years ago.

Groundbreaking technology

A large number of the high-tech antennae in the ALMA project were produced in Germany.

They were made with groundbreaking precision techniques - each one had to have the exact same properties and only then could they be connected to the eye of the telescope, the interferometer.

Andromeda nebula in space (Copyright: Flickr/Chris Lasley)

Scientists hope the telescope will shed light on the Big Bang and how the universe is changing

"The shape variation of the antennae had to be very accurate so that they could be processed into a signal. This means that if one antenna was much higher than the other antennae, the interferometer wouldn't work," says Peter Fasel, who is responsible for antenna technology at the German company Vertex.

Another issue is that the 12 meter high telescope mirror needs to withstand extreme temperature.

Technicians and engineers who put the telescope together tested it extensively at a base camp.

They wanted to know whether the panels had the right shape and whether the antennae could be aligned closely enough.

After the tests, the antennae were transported to their final location in the Atacama Desert.

Special trucks were made for the project to enable the transportation of more than 100 tons of equipment and have the individual radio telescopes set up with millimeter precision.

Successful test phase

Sixteen of the antennae went into operation in 2011. Wolfgang Wild says these first ALMA telescopes have yielded results better than any previous images. They have even made a discovery of small, organic sugar molecules.

"This sugar is the building block for life," says Wild. "Now we can speculate on whether life is widespread in the universe."

Astrophysicists around the world have been waiting eagerly for ALMA to go into full operation.

And it's finally ready - with all 66 antennae in place.

Its contribution to our understanding of the universe is greatly expected - and in part foreseeable. But Wolfgang Wild says there could also be surprises.

"It's a bit like Galileo," says Wild. "He probably hadn't expected to discover the Jupiter moons, but then he was surprised."

DW recommends