Mysterious gold stash found on hiking trail perplexes researchers

This week, uncover a stash of gold with murky origins, witness a cosmic joust, see why ancient fish are to thank for our sensitive teeth, and more.

​ This week, uncover a stash of gold with murky origins, witness a cosmic joust, see why ancient fish are to thank for our sensitive teeth, and more. Read More Breaking News, Latest News and Videos | CNN