Astronaut looks down from International Space Station at Earth and sees huge skull 'looking back'

An astronaut sitting up on the International Space Station (ISS) floating was startled to find a giant skull staring back at him from planet Earth.

As much of a bad omen as it looks, the explanation isn't as sinister.

Still, it’s quite unsettling to see a skull face staring back at you considering the vast darkness of space.

To make things more spooky, NASA shared the photo on Halloween 2023 though the photo was taken on February 12 of that year.

The spacecraft was passing above the Tibesti Massif - a mountain range in the Sahara Desert spanning Chad and Libya - when an astronaut noticed the skull-like formation imprinted on the Earth's surface. It presented a pale white coat with deep eye holes.

ISS/NASA

Well, it turned out to be a geological formation in Africa, with a couple of smouldering volcano cones forming the 'eyes' of the skull.

The area is known as Trou au Natron, or Doon Orei, which translates to 'natron hole' in French while Doon Orei is 'big hole' in Teda.

The formation is a 1,000-metre-deep volcanic caldera stretching about six to eight kilometres across, depending on where you measure from.

Whilst immensely impressive, Trou au Natron is not as old as its neighbouring volcanoes, according to NASA's Earth Observatory.

The bottom of the pit is covered in a substance called natron, a type of salt that consists of sodium carbonate, sodium bicarbonate, sodium sulphate, and sodium chloride.

Meanwhile, the black 'eyes' are volcanic cinder cones that have formed around the vents releasing energy from within Earth. And the darker area to the left of the face is a shadow cast from the tall rim of the crater, giving the skull its distinctive shape.

janiecbros / Getty

The highest mountains in the Sahara, stand at around 2,450 metres (8,040 feet) above sea level.

Interestingly, experts proposed Trou au Natron as once a thriving glacial lake until about 14,000 years ago. Today, it is barren and lifeless.

However, it remains a homeland to some diverse wildlife and the semi-nomadic Toubou people.

Surprisingly, this doesn't mark the first time a skull-shaped feature has been spotted from space.

In 2016, a weather satellite image captured Hurricane Matthew - a Category 5 tropical storm that claimed more than 600 lives across the Caribbean. But the radar instead portrayed the storm's swirling structure with a shadowed face, a bright red eye and distinct teeth. Scary!