NASA has recreated Mars' iconic "spiders" in a first-of-its-kind lab experiment, and you can watch it happen in this video.

Tests on Earth appear to confirm how the red planet's spider-shaped geologic formations are carved by carbon dioxide.

They're known as araneiforms, small systems of dark troughs that appear only in the southern polar region of Mars in the planet's spring. Exactly how the araneiforms emerge every Martian year has been something of a mystery.

As we've explored the Solar System's planets and moons using probes and orbiters, we have found and studied plenty of unusual features, from Jupiter's "Great Blue Spot" to signs of something stirring beneath Europa's ice.

A team of scientists at NASA have confirmed how Mars' 'spider' formations are carved by carbon dioxide. They were first discovered in 2003 and each formation can stretch more than half-a-mile from end-to-end.