How do craters form? That's a question that Felipe Pacheco-Vázquez of the Autonomous University of Puebla, Mexico, recently addressed by burying balloons in a sandbox and then popping them.

The experiment could help us better understand how craters form, specifically those that start from a process underground, such as methane explosions, which we're still learning a lot about. With news reports of these kind of craters turning up more regularly every year, understanding how and why they form could help us determine the causes and effects of such events.

Pacheco-Vázquez captured video of his experiment showing results that depict very clear-cut stages of explosion. First, he buried the balloon under the sand and then used a needle to pop it. The balloon exploded, creating a dome in the sand. This dome becomes larger until it eventually explodes outward. This creates a rim around the explosion area, pushing into the center of the area that sends up a plume of sand that eventually forms a crater.

Pacheco-Vázquez posted the entire process in a video outlining these different stages.

"We found very reproducible results and a morphology that was different from the one observed in impact craters," Pacheco-Vázquez said to New Scientist.

Typically, impact craters form when material gets thrown outward, but in this experiment, the burst itself leaves the hole that becomes a crater. According to Pacheco-Vázquez, this could also explain craters on other planets.

However, other scientists doubt the validity of this new study. For example, most believe that the craters on Mars happen without explosions and are just places where collapses occurred.

"I can't find a whole lot of geologically reasonable scenarios where that might show up," says Danielle Wyrick of the Southwest Research Institute in Texas.

However, Wyrick concurred that this phenomenon could happen on Earth's seafloor when methane bubbles up through it.

Such explosions are also more likely a response to human activity, such as oil drilling and nuclear blast tests, such as those tests done with nuclear weapons in the Nevada desert that started in the 1950s and ended in the 1990s, which left the land there looking similar to the surface of the moon.

The research was published in Physical Review Letters.

Photo credit: Dean Hochman | Flickr