Astonishing images show what a total solar eclipse looks like when viewed from space.

A spectacular solar event is underway today as large parts of the US will be able to view a total solar eclipse.

What makes this eclipse so special?

While they happen fairly regularly – about once every 18 months – solar eclipses are only visible at certain points on the Earth’s surface.

The eclipses follow a line along the Earth, with anyone who is on that line being able to see them.

A lot of the time this line crosses over the middle of the ocean or in a very remote place, in which case very few people will be able to see it, if anyone.

But less commonly the eclipse’s path will pass over an area where lots of people will be able to see it, as is the case today.

Who will be able to see tonight’s solar eclipse?

Beginning its tour of the US in south western Texas, the eclipse’s line will move north east before it exits the US all the way up in Maine.

And as long as you’re careful, you can view it if you’re on that line.

How a total solar eclipse looks from here on Earth. Space Frontiers/Hulton Archive/Getty Images

What does a total solar eclipse look like from space?

When we look up at an eclipse from the Earth, though for the sake of your eyesight please don’t look at it directly, we see the Moon moving across the Sun and blocking it out temporarily.

From space, this looks rather sinister as it is effectively the Moon casting its shadow over the Earth’s surface.

So viewing the event from space, you would see an enormous shadow being cast over the surface of the Earth.

Think of that scene in The Lord of the Rings when Sauron’s eye is turned to Gondor and shadow falls across it, except without a dark lord hell-bent on reclaiming their magic jewellery. At least one would hope.

And this is how it appears from space. NASA/JSC

Terry Virts is a former astronaut who worked on the International Space Station, and shared his experience of this remarkable event.

He told USA TODAY: “It was unlike anything I’ve ever seen. I joke I’m glad they told us there was an eclipse because it would have been unsettling to look down at Earth and see this black spot moving across. It was really cool.”

The astronaut described seeing an eclipse which not many people would have been able to see.

He said: “When I was in space in 2015, we saw an eclipse over the North Atlantic.

“It was an eclipse that very few humans saw I think, but it was a really unique experience to look down and just see this big black circle kind of moving across the planet.”