Planets are tough little buggers. They can form and survive in some extreme environments. In fact, the first confirmed planets outside our own solar system orbit the remnant of a dead star – a pulsar.

A pulsar is tiny – the size of a small city. But it’s more massive than the Sun. A teaspoon of its matter would weigh as much as a mountain. Yet a pulsar spins rapidly – up to several hundred times per second. It has an extreme magnetic field. The field shoots “jets” of particles out into space. As the pulsar spins, the jets can sweep across Earth like a lighthouse beacon, producing short pulses of energy.

The timing of those pulses is extremely precise. That makes pulsars some of the best clocks in the universe. But the timing can be changed by a companion – another star, or even a planet. And that’s how pulsar planets are discovered – through tiny changes in the timing of the pulses.

Eight pulsar planets have been confirmed. But they present quite a challenge. A pulsar is the remnant of a titanic explosion – a supernova. It’s hard to see how any planets could survive such a blast. So it’s likely that the planets formed after the blast – perhaps from debris from the explosion’s aftermath.

Regardless of how they formed, the planets aren’t friendly places. They’re blasted with charged particles, X-rays, and gamma rays from the pulsar. That may slowly erode the planets – no matter how tough they are.

Script by Damond Benningfield