The Earth's interior is composed of four layers, three solid and one liquid—not magma but molten metal, nearly as hot as the surface of the sun. The deepest layer is a solid iron ball ...

The sun may rise every morning, but the amount of sunlight reaching Earth's surface can substantially vary over decades, ...

For a few tense weeks earlier this year, asteroid 2024 YR4 loomed large in the minds of astronomers and the public alike.