1 | Lee-Thorp and her colleagues measured the levels of two isotopes of strontium, an element found in soil. | |
2 | Sharp and his colleagues studied what happened to two isotopes of the element chlorine during that process. | |
3 | Oxygen and strontium isotopes, which are fixed in dental enamel at the time of tooth formation, were tested in 18 subjects. | |
4 | But the team found that on the Moon it was about 25 times that of the terrestrial chlorine isotope ratio. | |
5 | That water signature is in the form of oxygen isotopes, atoms of oxygen with different numbers of neutrons. |