Astronomers at the University of Michigan believe about half the water in our solar system is older than the sun itself.
As it turns out, there are two types of water — the kind we're all used to, H₂O, and a heavier kind with an extra neutron in the hydrogen atom. We'll call them regular water and heavy water. According to the University of Michigan, "comets and Earth's oceans hold particular ratios of heavy water—higher ratios than the sun contains."
Our solar system was created in what the researchers call a planet-forming disk billions of years ago — dust and gas moved around our sun, eventually forming into our planets. But even before the creation of our eight planets (sorry, Pluto), the sun, and the planet-forming disk, were created in an even older cloud.
So in a question that's a whole lot like the "chicken or the egg" conundrum, the researchers were curious if the heavy water came from the older, sun-creating cloud or the younger, planet-creating cloud.
Find out more with this Newsy video.