Scientists looked at the amounts of noble gases in the water -- helium is one , for example -- and which isotopes were present . Barbara Sherwood Lollar is a geologist studying ancient water in mines . Water that she and her colleagues analyzed may be 2.6 billion years old . Hide Caption 1 of 10 Photos:
Barbara Sherwood Lollar is a geologist studying ancient water in mines . Water that she and her colleagues analyzed may be 2.6 billion years old . Hide Caption 1 of 10 Photos: