Astronomers assume they’ve discovered an ‘exomoon’ – a moon that exists exterior our personal photo voltaic system – based mostly on knowledge from NASA’s Kepler area telescope.

In a brand new paper, the consultants report the invention of a mysterious physique that’s virtually thrice the dimensions of Earth, which they assume is an exomoon. 

It is greater than 20,500 miles in diameter, in contrast with Earth’s diameter of seven,900 miles. 

It is orbiting a Jupiter-sized planet referred to as Kepler 1708b in one other photo voltaic system, 5,500 light-years away from Earth. 

The existence of any exomoon is but to be formally confirmed, though the primary potential candidate was recognized 4 years in the past. 

Since exomoons can’t be imaged straight, their presence is inferred after they move in entrance of a star, momentarily dimming the star’s mild. 

The discovery of a second exomoon candidate hints at the possibility that exomoons may be as common as exoplanets. This image shows an artist's impression of the potential exomoon

The invention of a second exomoon candidate hints on the chance that exomoons could also be as frequent as exoplanets. This picture reveals an artist’s impression of the potential exomoon


An exomoon is a moon that exists exterior our personal photo voltaic system.

They orbit exoplanets – planets exterior our photo voltaic system. 

The primary-ever sighting of an exomoon in 2018 continues to be awaiting affirmation.

Conversely, there are 4,905 confirmed exoplanets in 3,629 planetary techniques, and 1000’s extra exoplanets to be confirmed. 

The prefix ‘exo’ comes from Greek, which means exterior, outer or exterior.

Observations from different area telescopes, like Hubble, can be wanted to confirm the invention, a course of that might take years. 

If confirmed, the brand new sighting may imply that exomoons are as frequent within the universe as exoplanets (planets exterior our photo voltaic system). 

The invention was led by Professor David Kipping and his Cool Worlds Lab at Columbia College and has been revealed in Nature Astronomy. 

‘Astronomers have discovered greater than 10,000 exoplanet candidates thus far, however exomoons are far more difficult,’ stated Professor Kipping, who has spent the final decade looking for exomoons. ‘They’re terra incognita.’ 

Confirming the mysterious physique orbiting Kepler 1708b as an exomoon may take a very long time, contemplating the first-ever sighting of an exomoon 4 years in the past continues to be awaiting affirmation.

Verification of this latest candidate could possibly be equally as lengthy and contentious, in response to the staff. 

‘The method of affirmation would equally contain peer-review and past that scientific consensus amongst the astronomical neighborhood,’ Professor Kipping instructed MailOnline. 

‘Affirmation would require future observations on this case.’       

This is an artist impression of the Kepler Space Telescope that was decommissioned by NASA in 2018 after nearly a decade of service

That is an artist impression of the Kepler Area Telescope that was decommissioned by NASA in 2018 after almost a decade of service

Professor Kipping and his staff had been wanting on the pattern of the coldest fuel large planets captured by Kepler, which was decommissioned in 2018. 


Recognizing a moon or perhaps a planet a whole bunch to 1000’s of light-years from Earth is something however easy. 

Moons and planets can solely be noticed not directly as they move in entrance of their host stars, inflicting the star’s mild to intermittently dim. 

Catching certainly one of these fleeting transit indicators with a telescope is difficult, and so is decoding the light-curve knowledge. 

Exomoons are even tougher to detect than exoplanets as a result of they’re smaller and block much less mild.  

After scanning 70 planets in depth, they discovered only one candidate – Kepler 1708b – with a moon-like sign.

‘It is a cussed sign,’ stated Professor Kipping. ‘We threw the kitchen sink at this factor but it surely simply will not go away.’ 

Eric Agol, an astronomy professor at College of Washington, stated he is uncertain that this newest sign will change into actual, however others sounded extra optimistic. 

‘It’d simply be a fluctuation within the knowledge, both because of the star or instrumental noise,’ stated Professor Agol. 

Michael Hippke, an unbiased astronomer in Germany, stated the brand new discovery ‘is science at its greatest’. 

‘We discover an intriguing object, make a prediction, and both affirm the exomoon candidate or rule it out with future observations,’ he stated. 

‘I’m very excited to see a second exomoon candidate, though it’s unlucky that solely two transits have been noticed. Extra knowledge can be very cool.’ 

Kepler 1708b is a world 5,500 light-years from Earth within the course of the Cygna and Lyra constellations.   

Its newly-discovered potential exomoon is a couple of third smaller than the Neptune-sized potential exomoon that Professor Kipping and his colleagues earlier discovered orbiting an identical Jupiter-sized planet, Kepler 1625b, reported in a 2018 analysis paper.

Each candidates are possible fabricated from fuel that has piled up underneath the gravitational pull attributable to their monumental dimension.

In addition they could have even began life as planets, solely to be pulled into the orbit of a good greater planet like Kepler 1625b or Kepler 1708b.

An exoplanet is simply a planet outside of our own Solar System. This is an artistic rendering of what an exoplanet might look like, with its star in the background (stock image)

An exoplanet is just a planet exterior of our personal Photo voltaic System. That is a creative rendering of what an exoplanet would possibly seem like, with its star within the background (inventory picture)

Each potential moons are positioned removed from their host star, the place there’s much less gravity to tug at planets and strip off their moons.

Actually, the researchers sought out chilly, large fuel planets on large orbits of their seek for exomoons exactly as a result of the analogue in our personal photo voltaic system, Jupiter and Saturn, have greater than 100 moons between them.

If different moons are on the market, they’ll possible be smaller and tougher to identify. 

‘The primary detections in any survey will usually be the weirdos,’ Professor Kipping stated. ‘The large ones which can be merely best to detect with our restricted sensitivity.’

Exomoons fascinate astronomers for a similar causes that exoplanets do – they’ve the potential to disclose how and the place life could have emerged within the universe.

Astronomers wish to understand how these exomoons type, if they’ll maintain life, and what function, if any, they play in making their host planets liveable.

Professor Kipping recalled how the existence of exoplanets was greeted with the identical skepticism as exomoons are as we speak. 

‘These planets are alien in comparison with our house system,’ he stated. ‘However they’ve revolutionised our understanding of how planetary techniques type.’   


The now retired Kepler telescope spent almost a decade in area on the lookout for Earth-size planets orbiting different stars, however scientists are nonetheless analysing its knowledge. 

Kepler launched in 2009 and was decommissioned by NASA in 2018 when it ran out of gas wanted for additional science operations. 

It was launched by NASA particularly for figuring out exoplanets. 

Since its launch in 2009, Kepler noticed 1000’s of exoplanets exterior our photo voltaic system, regardless of experiencing mechanical failures and being blasted by cosmic rays. 

In 2013, Kepler’s major mission was concluded when a second response wheel broke, which meant that the area craft could not maintain a gradual stare upon its unique area of view.

However Kepler was given a ‘new lease on life’ by NASA on its K2 mission, which required it to shift its area of view to new parts of the sky about each three months. 

NASA initially assumed that K2 would solely be capable to conduct 10 campaigns with the remaining gas, but it surely went on to full an astonishing 16 campaigns.