 Yes, spelled P-A-W. Find these deals and more at WTOP.com. Valerie Bonk, WTOP News. NASA's Curiosity rover has made what scientists are calling its most unusual find on Mars so far. WTOP's Michael Toscano tells us it's pure sulfur. Curiosity is currently exploring the Geddes-Vallis Channel, a 3 billion year old winding and debris filled pathway.