IT left Earth 33 years ago, now it's claimed the Voyager 2 spacecraft may have been hijacked by aliens after sending back data messages NASA scientists can't decode.

NASA installed a 12-inch disk containing music and greetings in 55 languages in case intelligent extraterrestrial life ever found it.

But now the spacecraft is sending back what sounds like an answer: Signals in an unknown data format!

The best scientific minds have so far not been able to decipher the strange information – is it a secret message?

Alien expert Hartwig Hausdorf said:"It seems almost as if someone had reprogrammed or hijacked the probe – thus perhaps we do not yet know the whole truth"  Read more in Bild

Engineers are working to solve the data transmissions from the Voyager 2 spacecraft near the edge of the solar system, NASA's Jet Propulsion Laboratory said today.

The spacecraft late last month began sending science data 8.6 billion miles to Earth in a changed format that mission managers could not decode.

Engineers have since instructed Voyager 2 to only transmit data on its own health and status while they work on the problem.

Launched in 1977, Voyager 2 and its twin, Voyager 1, explored the giant planets Jupiter, Saturn, Uranus and Neptune and kept on going. Nearly 33 years later, they are the most distant human-made objects.

Voyager 1 is 10.5 billion miles from Earth and in about five years is expected to pass through the heliosphere, a bubble the sun creates around the solar system, and enter interstellar space.

Voyager 2 will follow after that.