Lying beneath the tranquil settings of Yellowstone National Park in the US lies an enormous magma chamber. It’s responsible for the geysers and hot springs that define the area, but for scientists at Nasa, it’s also one of the greatest natural threats to human civilisation as we know it: a potential supervolcano.

Following an article we published about supervolcanoes last month, a group of Nasa researchers got in touch to share a report previously unseen outside the space agency about the threat – and what could be done about it.

“I was a member of the Nasa Advisory Council on Planetary Defense which studied ways for Nasa to defend the planet from asteroids and comets,” explains Brian Wilcox of Nasa’s Jet Propulsion Laboratory (JPL) at the California Institute of Technology. “I came to the conclusion during that study that the supervolcano threat is substantially greater than the asteroid or comet threat.”