Since Sans has learned that story about the canyon maybe being created when something fell from space, he is going to check on that. He'll grab a large sample size of rocks both from around the lake and from the canyon walls. He'll cut into the canyon walls and the rocks that form the lake, though he is not actually going into the lake--he's just taking pieces from the bank where it's dry and leech-free. He'll go take over some space at the dig site to evaluate these rocks for signs of impact. Dig site employees everywhere will be shocked Sans knows how to use a microscope. Will he find signs of some sort of space-related impact?