DEPTHX , an autonomous robot capable of exploring and mapping out underwater caverns, has finally succeeded in its quest to explore the deepest sinkhole in the world, Cenote Zacatón. DEPTHX is short for Deep Phreatic Thermal Explorer wherein the word phreatic means underground water. DEPTHX is funded by NASA and is a joint project of Stone Aerospace and researchers from Southwest Research Institute, Colorado School of Mines, University of Texas at Austin, University of Arizona and the Carnegie Mellon University.

DEPTHX is not tied to the surface on a boat but makes its way alone as it explores flooded underground caves by the use of 56 SONAR sensors that feeds information to a highly sophisticated software that interprets what it sees and enables it to navigate on its own. The data is also used by DEPTHX to produce an accurate three-dimensional map of the interior surfaces of the caverns it explored.

DEPTHX’s achievement is unique not just because of the depth of the place it explored, since other AUVs (autonomous underwater vehicles) have already been used to map out parts of the ocean floor, but because of the fact that it was a sinkhole that it explored. Other AUVs might be able to go as deep as DEPTHX did but they do not have the sensitivity and maneuvering ability to be able to move around spaces as tight and as irregular as the bottom of Cenote Zacatón.

Cenote Zacatón has actually claimed a diver, Sheck Exley, who attempted to find out its depth back in 1994 after reaching 925 feet. Now a robot has finally reached the bottom of Cenote Zacatón and was able to create the first 3D maps of Zacatón and La Pilita, a smaller water-filled sinkhole nearby.