When stars like our own sun die they will become white dwarfs. As a star like our sun is running out of fuel in its core it begins to bloat into a red giant. This will happen to our sun in 5 Billion years. The inner planets, Mercury, Venus, Earth, and Mars will all be consumed by the sun's expanding surface. Then after a few million years the outer layers of the red giant will begin to puff off and form a planetary nebula. Leaving behind only the dead core of the star made of mostly carbon and oxygen. This is the white dwarf.

A typical white dwarf is about the size of the Earth. It is also very dense and hot. A spoonful of white dwarf material on Earth would weigh as much as a car. Strange, isn't it?