Deep matters

The Deep Phreatic Thermal Explorer (DEPTHX) has reached the bottom of the world's deepest sinkhole. According to researchers involved with the project, the robotic vehicle was able to explore 318 meters below the surface, a depth never met. The El Zacaton sinkhole, the world's deepest, does not have any tunnels or underwater connections with other sinkholes in the area.

NASA wants the Stone Aerospace robot to search Europa, one of Jupiter's icy moons. The depth and reliability tests in Earth's deepest sinkhole were a crucial step towards a possible trip to Europa.