ASTRONAUTS aboard the International Space Station (ISS) have captured the 'once in a lifetime' Comet A3 zooming through breathtaking Aurora.

Matthew Dominick and Dom Pettit, who are both avid astro-photographers, spotted the space rock before it was visible to the naked eye by using orbital geometry and math.

"It is totally awesome to see a comet from orbit," Pettit wrote in a post on social media platform X (formerly Twitter).

"The perspective of rising through the atmosphere on edge is truly unique from our vantage point.

"The comet tail is still too dim to see with your eyes, but it is heading towards the sun and growing brighter every day."

Comet C/2023 A3, also known as Tsuchinshan-ATLAS, will be visible from Earth between 27 September and 2 October.

The space rock comes from the Oort Cloud, a giant shell around our solar system that hosts millions of comets and other icy pieces of debris.

It is characterised by the long, two-pronged tail of dust and ice that follows it, which experts say will be illuminated white and blue by the sun.

It's this tail that also makes it more visible to stargazers on Earth during its peak brightness.

An amateur astronomer told Pettit that the comet would be about 20 degrees ahead of the sun from the perspective of the ISS around 22 September, before it became fully visible.

Dominick explained: "We needed photos to be taken when we were on the dark side of the Earth because the comet is still very dim.

"We have software on the ISS that tells us when orbital sunrise will occur.

"So we did a simple estimate to figure out when and where to point the cameras.

"You can imagine how we felt when it appeared. Math works!"

Comet A3 is currently moving towards the sun and will disappear tomorrow, before reappearing again on 12 October.

And after that date, it won't fly by Earth again for another 80,000 years.

In early September, Dominick caught a giant white and green flash on camera, in the sky above the Mediterranean Sea.

The footage, available above, shows a split-second white and green explosion, completely dwarfing any nearby lightning strikes.

At the time, Dominick, who launched to the orbital outpost in March, sought advice from friends who said the blast was a meteor burning up in Earth's atmosphere.

Dominick wrote in a post on X: "I showed this to a couple of friends yesterday to see what they thought.

"They both thought it was a meteor exploding in the atmosphere - a rather bright one called a bolide.

"Timelapse is slowed down to one frame per second for you to see it streaking and then exploding."

Bolide explosions are rare, and happen very quickly.