Astronomers are stunned after spotting the first interstellar object from beyond our solar system streaming past the earth at an astonishing 25 kilometres per second.

University of Hawaii Institute for Astronomy astronomer Rob Weryk told The New York Times, “We’ve never seen anything like this before.”

Dr Weryk first saw the mysterious object on October 19 while reviewing images captured by the university’s Pan-STARRS 1 telescope on the island of Maui.

He said he first thought the object was a type of space rock, known as a ‘near earth object’, but later realised its motion did not make sense.

The object was moving much faster than any asteroid or comet he had seen before and he quickly realised it was not from the Earth’s solar system.

“It’s moving so fast that the sun can’t capture it into an orbit,” Dr Weryk said.

The International Astronomical Union’s Minor Plant Centre said further observations confirmed the unusual nature of the object’s orbit and said the object “may be the first clear case of an interstellar comet”.

“Further observations of this object are very much desired,” the Centre said in its report.

The University of Hawaii’s Pan-STARRS 1 telescope on Haleakala Hawaii named the mysterious object A/2017 U1.

It’s believed the unknown rock came from the direction of the constellation Lyra and is less than 400 metres in diameter.

NASA’s Centre for Near-Earth Object Studies manager Paul Chodas told The Independent scientists had been waiting for a sighting like this for decades.

“It’s long been theorised that such objects exist – asteroids or comets moving around between the stars and occasionally passing through our solar system,” Mr Chodas said.

“But this is the first such detection. So far, everything indicates this is likely an integral object, but more data would help confirm it.”

NASA colleague Davide Farnocchia said the mysterious object had the most extreme orbit he had ever seen.

“It is going extremely fast and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back.”

Astronomers are now trying to refine their observations and data to pinpoint exactly where the mysterious object came from.

If the object is interstellar, the next step will be to determine which star the object has come from.