Pulsars

A pulsar is a very small, super-dense star. It spins around very fast and sends out beams of radio waves. As the pulsar spins, the beams sweep across space. When the beam points at Earth, we can see a pulse of energy. That is why they are called pulsars.

What Pulsars Are Made Of

Pulsars are a kind of neutron star. They form when a big star explodes as a supernova. What is left is a tiny, very heavy core. A pulsar is only about 12 miles across. But one teaspoon of it would weigh billions of tons.

Spinning Super Fast

Pulsars spin very quickly. Some spin once every few seconds. Others spin hundreds of times every second. The fastest pulsars are called millisecond pulsars. Their signals are so regular that scientists use them like clocks in space.

Fun Facts

• The first pulsar was discovered in 1967 by Jocelyn Bell Burnell.
• Pulsars were once nicknamed LGM, which stood for 'Little Green Men.'
• The fastest known pulsar spins 716 times each second.

Did You Know?

Scientists once sent a map showing Earth's location using pulsars as landmarks on the Pioneer and Voyager spacecraft.