NASA’s Hubble spacecraft discovers evidence of a weather system on nearby ‘Hot Jupiter’

NASA’s Hubble spacecraft discovers evidence of a WEATHER system on nearby ‘Hot Jupiter’ exoplanet – despite blistering surface temperatures of 2,192°F

  • Researchers examined images of WASP-31b taken by the Hubble telescope 
  • WASP-31b is an extremely hot ‘puffy planet’ 1,305 light years away from Earth 
  • It is tidally locked, with one side facing the star and the other facing out to space
  • Temperatures can reach as high as 2,192F in the zone between day and night
  • This is where researchers say the chemical chromium hydride could transform between liquid and gas and produce strong winds from day to night side

NASA‘s Hubble Space telescope has spotted potential signs of a weather system on a blisteringly hot Jupiter-sized exoplanet, with surface temperatures of 2,192F. 

Researchers from SRON Netherlands Institute for Space Research and the University of Groningen examined images of WASP-31b taken by the famous telescope. 

WASP-31b is is tidally locked, with one side always facing its host Sun-sized star – in the ‘twilight zone’ between the two zones temperatures reach 2,192 degrees F. 

The experts found evidence of chromium hydride in this zone – at temperatures and pressure levels that could allow it to transform between liquid and gas – forming a weather system as it rains on the night side and as a gas on the day side.

This is an important discovery, the team say, as a weather system is a key feature astronomers look for when finding a planet that is suitable for life – and finding one on such an inhospitable world could make the process easier for ‘friendlier planets’. 

NASA’s Hubble space telescope has spotted evidence of a weather system on a ‘hot Jupiter’ exoplanet – suggesting the world could have conditions suitable for life 

In the 'twilight zone' - the area between the star and space side - temperatures can reach as high as 2,192 degrees Fahrenheit (2,100 C)

In the ‘twilight zone’ – the area between the star and space side – temperatures can reach as high as 2,192 degrees Fahrenheit (2,100 C)

WASP-31b: A HOT-JUPITER EXOPLANET 

  • NAME: WASP-31b
  • DISCOVERED IN: 2010
  • MASS: 0.478 the size of Jupiter
  • RADIUS: 1.537 the size of Jupiter
  • ORBITAL PERIOD: 3.4 days
  • DETECTION METHOD: Transit
  • TYPE: Hot-Jupiter gas giant
  • ORBITAL RADIUS: 0.046 of Earth
  • DISTANCE FROM EARTH: 1,305 ly

It orbits an F-type star that is about 1,300 light years from the Earth and about the same size as the Sun.

It is classed as a ‘puffy’ type of planet, with a mass half that of Jupiter but one and a half times its radius. 

WASP-31b is a ‘puffy world’ that is about 1.5 times the size of Jupiter but with about half its mass – it orbits its host star dwarf star every 3.4 days. 

‘Hot Jupiters, including WASP-31b, always have the same side facing their host star,’ says co-author and SRON Exoplanets program leader Michiel Min. 

‘We therefore expect a day side with chromium hydride in gaseous form and a night side with liquid chromium hydride. 

‘According to theoretical models, the large temperature difference creates strong winds. We want to confirm that with observations.’ 

Exoplanets are currently too far away for human-built probes to reach, but telescopes and Earth-based equipment can offer a glimpse into their atmosphere.

They can use fingerprints in the atmosphere – including signs of certain chemicals and temperatures they are found at – to determine things like weather systems.

These fingerprints allow astronomers to deduce which substances are in the atmosphere of an exoplanet – and one day use that to find evidence of alien life.

One sign life might exist is finding evidence of a weather system on a planet, according to Dutch researchers.

While the ‘puffy’ WASP-31b is likely too hot for life to evolve, finding evidence of a weather system within the atmosphere helps astronomers learn more about how possible weather systems on alien and unusual worlds could form.

WASP-31b is an 'intense planet' 1,305 light years away from the Earth - the planet is tidally locked, with one side always facing the star and the other out to space

WASP-31b is an ‘intense planet’ 1,305 light years away from the Earth – the planet is tidally locked, with one side always facing the star and the other out to space

Researchers from SRON Netherlands Institute for Space Research and the University of Groningen examined images of WASP-31b taken by the famous telescope

Researchers from SRON Netherlands Institute for Space Research and the University of Groningen examined images of WASP-31b taken by the famous telescope

CHROMIUM HYDRIDE (CrH): AN INORGANIC COMPOUND

Chromium hydride is an inorganic compound that is found naturally in some stars.

When it is produced in a reaction with chromium vapour, the compound gas glows bright bluish-green.

It has been discovered in a number of stars and has been used to identify some brown dwarf stars.

A recent study found the chemical compound in the hot Jupiter exoplanet WOLF-31b where it could be transitioning between gas and liquid.

The liquid form rains down on the night side, with the gas in the air of the day side of the tidally locked world. 

Finding chromium hydride at the boundary between liquid and gas is reminiscent of clouds and rain – at least it is in the case of water on Earth.

First author Marrick Braam and his colleagues found evidence in Hubble data for chromium (CrH) in the atmosphere of exoplanet WASP-31b.

This is the first time it has been found on a hot Jupiter planet and at the right pressure and temperature for it to operate as a weather system. 

‘We should add that we only found chromium hydride using the Hubble space telescope,’ said Braam, adding that they didn’t see it in ground based telescopes including the European Southern Observatory Very Large Telescope in Chile. 

They won’t be able to confirm whether the chromium really is evidence of a weather system on the planet until Hubble’s successor – the James Webb Space Telescope (JWST) is launched later this year.

The Dutch team hope to use it to investigate WASP-31b, and other hot Jupiter-type planets, to confirm if and how a weather system would operate. 

Co-author Floris van der Tak says, ‘With JWST we are looking for chromium hydride on ten planets with different temperatures, to better understand how the weather systems on those planets depend on the temperature.’ 

The findings have been published in the journal Astronomy and Astrophysics

Scientists study the atmosphere of distant exoplanets using enormous space satellites like Hubble

Distant stars and their orbiting planets often have conditions unlike anything we see in our atmosphere. 

To understand these new world’s, and what they are made of, scientists need to be able to detect what their atmospheres consist of.  

They often do this by using a telescope similar to Nasa’s Hubble Telescope.

These enormous satellites scan the sky and lock on to exoplanets that Nasa think may be of interest. 

Here, the sensors on board perform different forms of analysis. 

One of the most important and useful is called absorption spectroscopy. 

This form of analysis measures the light that is coming out of a planet’s atmosphere. 

Every gas absorbs a slightly different wavelength of light, and when this happens a black line appears on a complete spectrum. 

These lines correspond to a very specific molecule, which indicates it’s presence on the planet. 

They are often called Fraunhofer lines after the German astronomer and physicist that first discovered them in 1814.

By combining all the different wavelengths of lights, scientists can determine all the chemicals that make up the atmosphere of a planet. 

The key is that what is missing, provides the clues to find out what is present.  

It is vitally important that this is done by space telescopes, as the atmosphere of Earth would then interfere. 

Absorption from chemicals in our atmosphere would skew the sample, which is why it is important to study the light before it has had chance to reach Earth. 

This is often used to look for helium, sodium and even oxygen in alien atmospheres.  

This diagram shows how light passing from a star and through the atmosphere of an exoplanet produces Fraunhofer lines indicating the presence of key compounds such as sodium or helium 

This diagram shows how light passing from a star and through the atmosphere of an exoplanet produces Fraunhofer lines indicating the presence of key compounds such as sodium or helium