At first, the universe was like a hot stew. Instead of carrots and potatoes, it had particles. As the soupy universe cooled, ...

Earth formed around 4.54 billion years ago. Knowing how old Earth is can be more difficult to confirm because Earth's age is not only based on the age of rocks, but also the isotopic estimates of what ...

I asked my friend Julie Ménard how Earth formed. She’s a planetary scientist at Washington State University. She told me it started with the Big Bang. That was nearly 14 billion years ago. “The Big ...

Scientists have long believed that the Moon was formed by a massive object crashing into the Earth billions of years ago and sending chunks hurtling into space that ultimately coalesced. But what was ...

One bright day on Earth about 4.5 billion years ago, everything changed. A massive object slammed into the young planet. The impact was so large that bits were flung out into space, eventually ...