 Scientists have now discovered a cave. And researchers say there could be hundreds more caves and tunnels, which they say could potentially house future astronauts. An Italian-led team reporting today there's evidence of a sizable cave accessible from the deepest known pit on the moon in the area of what's known as the Sea of Tranquility. It's believed to have been created by the collapse of a lava tube. Crude oil futures prices moved lower today, oiled down 30 cents a barrel to $81.91 a barrel in New York.