Approximately 4.6 billion years ago, our solar system formed from a cloud of gas and dust called a solar nebula that swirled around, eventually collapsing under its own gravity into a rapidly rotating ...

A team of researchers recently reported that a little over 4 pounds of helium-3 leak out of Earth every year, an indication that our planet formed in a solar nebula. Helium-3 is a very ancient isotope ...