'Real-life Death Star' can protect the Earth from asteroids

A team at the University of California has devised a real-life version of the Death Star from Star Wars to protect the Earth from asteroids – and say the technology to make it already exists.

It's been named the 'De-Star', partly in homage to the film's space station. It stands for Directed Energy System for Targeting of Asteroids and exploRation.

The De-Star would be an unmanned satellite used to protect the Earth from potentially catastrophic collisions with asteroids. It would detect approaching space rocks that might pose a threat and target them with a high-energy laser beam.

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The laser would heat one part of the rock, causing it to emit gas and alter the asteroid's direction – hopefully moving it away from the Earth.

It is an idea that has "been around for years", the Daily Telegraph says, but the exciting development is that the team from California believe that it could actually be built now – and would work.

The technology has been tested on Earth, with beams fired at pieces of basalt, which has a similar composition to some asteroids. They found that the basalt started to lose mass when it glowed white hot through a process known as sublimation, or vaporisation, which turns a solid or liquid into a gas.

The gas causes a "plume cloud", one of the team told the Telegraph, "which generates an opposite and equal reaction, or thrust".

Using the technique, the team managed to slow and reverse the rotation of a piece of spinning basalt.

However, there is a catch – deploying the De-Star successfully would need plenty of warning. It would take 30 years for a 10kW laser to deflect an asteroid measuring 328ft wide.

As well as not having Darth Vader on board, the De-Star differs from the Death Star in scale – it would be much, much smaller. The team are working on an even smaller version that would fly alongside asteroids as a last line of defence.