Seven dark patches were found on Mars near a volcano, and dubbed the seven sisters, by researchers last month.

This week, they focused in on one of them, and it appears to be a very deep hole. A hole that could most likely be able to reach a depth inside Mars that would be warm enough to have liquid water.

I can’t wait until the Mars Bats Invasion.

The geological oddity measures some 330 feet (100 meters) across and is located on an otherwise bright dusty lava plain to the northeast of Arsia Mons, one of the four giant Tharsis volcanoes on the red planet.

The hole might be the sort of place that could support life or serve as a habitat for future astronauts, researchers speculated.