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 ...

WASHINGTON — Helium-3, a rare isotope of helium gas, is leaking out of Earth’s core, a new study reports. Because almost all helium-3 is from the Big Bang, the gas leak adds evidence that Earth formed ...