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For the first time, British scientists have detected temperature fluctuations on a rocky planet outside our solar system.

Named 55 Cancri e, researchers have found that the so-called 'diamond planet' can have temperatures swinging from between 1,000-2,700°C.

They believe the readings could be due to massive amounts of volcanic activity on the surface.

Astronomers have detected wildly changing temperatures on a super Earth – the first time any atmospheric variability has been observed on a rocky planet outside the solar system – and believe it could be due to huge amounts of volcanic activity

The ability to peek into the atmospheres of rocky 'super Earths' and observe conditions on their surfaces marks an important milestone in finding alien life. 

The nearly threefold change in temperature over a two year period was detected by researchers led by the University of Cambridge.  

Using Nasa's Spitzer Space Telescope, the researchers saw thermal emissions coming from the planet, called 55 Cancri e.

The planet is orbiting a sun-like star located 40 light years away in the Cancer constellation. 

'This is the first time we've seen such drastic changes in light emitted from an exoplanet, which is particularly remarkable for a super Earth,' said Dr Nikku Madhusudhan of Cambridge's Institute of Astronomy, a co-author on the new study.

55 Cancri e is a 'super Earth': a rocky exoplanet about twice the size and eight times the mass of Earth. The planet is orbiting a sun-like star located 40 light years away. Pictured is an artist's impression 

'No signature of thermal emissions or surface activity has ever been detected for any other super Earth to date.'

The researchers believe the variability in temperature could be due to huge plumes of gas and dust which occasionally blanket the surface and may be partially molten.

The plumes could be caused by exceptionally high rates of volcanic activity, higher than what has been observed on Io, one of Jupiter's moons and the most geologically active body in the solar system.

'We saw a 300 per cent change in the signal coming from this planet, which is the first time we've seen such a huge level of variability in an exoplanet,' said Dr Brice-Olivier Demory of the University's Cavendish Laboratory, lead author of the new study. 

55 Cancri e is a 'super Earth': a rocky exoplanet about twice the size and eight times the mass of Earth.

It is one of five planets orbiting a sun-like star in the Cancer constellation, and resides so close to its parent star that a year lasts just 18 hours. 

The planet is also tidally locked, meaning that it doesn't rotate like the Earth does – instead there is a permanent 'day' side and a 'night' side. 

Since it is the nearest super Earth whose atmosphere can be studied, 55 Cancri e is among the best candidates for detailed observations of surface and atmospheric conditions on rocky exoplanets.

Most of the early research on exoplanets has been on gas giants similar to Jupiter and Saturn, since their enormous size makes them easier to find. 

In recent years, astronomers have been able to map the conditions on many of these gas giants, but it is much more difficult to do so for super Earths: exoplanets with masses between one and ten times the mass of Earth.

Earlier observations of 55 Cancri e pointed to an abundance of carbon, suggesting that the planet was composed of diamond. 

'When we first identified this planet, the measurements supported a carbon-rich model,' said Madhusudhan, who along with Demory is a member of the Cambridge Exoplanet Research Centre. 

'But now we're finding that those measurements are changing in time. The planet could still be carbon rich, but now we're not so sure – earlier studies of this planet have even suggested that it could be a water world. 

'The present variability is something we've never seen anywhere else, so there's no robust conventional explanation.

'But that's the fun in science – clues can come from unexpected quarters.'