UFO sighting of ‘alien spaceship’ aboard ISS turned out to be Russian urine

British astronaut Tim Peake has recalled the moment he thought he saw a UFO in space during his time aboard the International Space Station (ISS).

Major Peake became the first British astronaut to join the ISS when he spent six months aboard the orbiting laboratory in 2015.

During his time onboard, Major Peake said he once saw “three lights moving in formation”, before they were joined by a fourth.

“We were perplexed, until we realised that what we thought were the far away lights of alien spaceships were actually very close small droplets,” Major Peake told The Graham Norton Show.

“What was happening was liquid leaking out of a Russian probe vehicle, crystallising instantly and reflecting the light. What we were seeing was Russian urine.”

Major Peake hopes to return to space in the next few years, despite the initial trepidation he felt on his first mission.

“There is always a thought at the back of my mind that I am rolling the dice, but the overriding feeling is of adrenalin-fuelled excitement,” he said.

“I’d love to [go back], absolutely. In fact, we are all slated for a second mission between now and 2024. I’m waiting by the phone.”

Earlier this year, the US Department of Defense released videos of what they described as “unexplained aerial phenomena”, prompting theories that they show alien UFOs.

The three videos released were captured by US pilots in 2004 and 2015, but only released this year after the footage was leaked to the New York Times.

One of the pilots who captured the 2004 footage described an oblong object hovering above the Pacific Ocean, saying “it accelerated like nothing I’ve ever seen."

In response to the videos, Senate Democratic leader Harry Reid said the Pentagon should take a “serious, scientific look at this”, adding, “it only scratches the surface of research materials available".

The Pentagon said in a statement at the time: “After a thorough review, the department has determined that the authorised release of these unclassified videos does not reveal any sensitive capabilities or systems, and does not impinge on any subsequent investigations of military air space incursions by unidentified aerial phenomena.”