Humanity's First-Ever Exoplanet Discovery Was an Unbelievable Fluke

There was planetary history in the early 1990s. The discovery of the first planets outside the Solar System was announced in 1992.

The two extrasolar planets were intriguing. They were rocky worlds 4.3 and 3.9 times the mass of Earth, and they were circling around a type of dead star called a millisecond pulsar. The third exoplanet was 0.2 times the mass of Earth.

An analysis of hundreds of pulsars has shown that exoplanets are extremely rare.

Only around 3,320 s Pulsars are known in the stars. Less than 1% of those are likely to have Earth-like worlds in the sky. There are just 16 radio waves.

There are hundreds of millisecond pulsars known in the universe. That makes the discoveries of the first exoplanets pretty incredible.

The dead stars are interesting, but they add a bit of a kick.

The core of a dead star that has reached the end of its atomic fusion lifespan ejected most of its outer material and collapsed into an object whose density is only surpassed by black holes. The mass of a nova can be up to 2.3 times that of the Sun.

A rotating neutron star has a beam of radiation shooting from it's poles. The star's beams sweep past Earth as it rotates, making it appear to pulse. Think of a lighthouse with lots of light.

Because of the fast rotation of some pulsars, there are light pulse on the scales. If you want to understand what that means, you can listen to the radio waves.

The environment is very extreme. There are a number of other pulsars that have been discovered with exoplanets. Most of these planets are giants, and those that aren't can get a bit weird, like an ultra dense world that is thought to be the remains of a white dwarf star.

Iuliana Niu is an astronomer at the University of Manchester in the United Kingdom. The Jodrell Bank Observatory in the UK was used to conduct a survey of 800 pulsars.

Niu said thatPulsars are very interesting and exotic.

Thirty years ago, the first extrasolar planets were discovered, but we don't know how these planets can survive in such extreme conditions. It is crucial to find out how common these are.

They wanted to find worlds from 1 percent of the Moon's mass up to 100 times the mass of Earth. The larger of the two worlds, Poltergeist and Phobetor, has a 66 and 98 day period.

Two-thirds of the pulsars are not likely to host exoplanets heavier than Earth, and less than 1% are likely to host exoplanets in the mass range of Poltergeist and Phobetor.

It's difficult to gauge the presence of exoplanets similar to Draugr.

Draugr would not be seen in most of the sample because it would get lost in noise. It's not clear if it's possible for the tiny worlds to exist outside a multi-planet system.

There were 15 periodic signals that could be related to exoplanets. The team thinks that most of them can be attributed to the magnetosphere. A promising candidate for follow-up exoplanet surveys was the PSR J2007+3 120.

The team concluded that only a small percentage of pulsars are likely to have Earth-like worlds.

There is no bias towards any range of exoplanet size or mass found in the team's findings. Any such exoplanets around a pulsar would have an elliptical path. The process that produced planets around baby stars in the Solar System was different from the one that produced planets around other stars.

The team presented their research at the National Astronomy Meeting in the UK and it was published in the Monthly Notices of the Royal Astronomical Society.