More than 100 new exoplanets found as scientists hunt for 'second Earth'

The planets help our search for another place that supports life like our planet – and helps set our home in context

After detecting the first exoplanets in the 1990s it has become clear that planets around other stars are the rule rather than the exception and there are likely hundreds of billions of exoplanets in the Milky Way alone. The search for these planets is now a large field of astronomy (ESA/Hubble/ESO/M. Kornmesser)

Scientists have found almost 100 new planets outside our solar system.

The worlds – which vary from being the same size as our own Earth to much bigger like Jupiter – were found amid hundreds of potential exoplanets found in data from the Kepler spacecraft.

They were discovered as part of scientists' search for other worlds like our own, some of which might contain life just like our own. But they also set our own planet and its solar system in context, helping us learn just how normal we are.

They were discovered using research from National Space Institute (DTU Space) at the Technical University of Denmark. Out of 275 candidate planets, scientists confirmed 95 were exoplanets.

The spacecraft, which is on the K2 mission to discover new exoplanets, has uncovered thousands of candidates since it was launched almost a decade ago.

Andrew Mayo, lead author of the study and PhD student, said: "We started out analysing 275 candidates of which 149 were validated as real exoplanets. In turn, 95 of these planets have proved to be new discoveries."

A candidate exoplanet is measured by the shadow it causes as it crosses its host star.

It is given a closer look before it is confirmed to be an exoplanet - but the task is not an easy one as scientists must differentiate between signals from a candidate and signals from other spacecraft.

Mr Mayo said: "We found that some of the signals were caused by multiple star systems or noise from the spacecraft.

"But we also detected planets that range from sub Earth-sized to the size of Jupiter and larger."

His team found a planet on a 10-day orbit around a bright star named HD 212657. The discovery was deemed significant because the bright star enables the planets to be observed from "ground-based observatories".

The work was published in the Astronomical Journal and researchers from Nasa, UC Berkeley and the University of Tokyo were involved in the study.

The Kepler spacecraft was launched in 2009 and was re-purposed by engineers and astronomers after a mechanical failure in 2013.

This gave way to the ongoing K2 mission to search for exoplanet transits.

Some 3,600 exoplanets have been found since the first one, 51 Pegasi b, was discovered orbiting a Sun-like star in 1995.

They range in size from Earth-like to Jupiter-sized.

Mr Mayo said: "Exoplanets are a very exciting field of space science. As more planets are discovered, astronomers will develop a much better pictures of the nature of exoplanets which in turn will allow us to place our own solar system into a galactic context."

Upcoming missions will examine the rocky, Earth-sized planets which could support life.

Additional reporting by agencies