In this diagram, the red lines represent the edges ... There are no elements in this part of the Earth's structure that can be easily extracted. The mantle is the thickest layer of the Earth ...

Researchers from the Australian National University used seismic waves generated by earthquakes to peer into the Earth's mysterious ... This donut-like structure runs parallel to the equator ...

Earth may be huge to us, but it's only a tiny part of our Milky Way Galaxy, which is just a small part of the universe. In fact, the biggest structure in the universe that scientists know about is ...