“However, up until now helium had not been detected on exoplanets—despite searches for it.”

But now, using Wide Field Camera 3 on NASA’s Hubble Space Telescope, Spake’s team managed to detect this strangely elusive substance, marking the first time that helium has been detected on a planet outside of our Solar System. Just recently, an international team of astronomers, led by Jessica Spake from the University Of Exeter, United Kingdom, used the space telescope to analyze the starlight passing through the upper atmosphere of an exoplanet dubbed WASP-107b and discovered helium in abundance. The breakthrough, made from observations using the Hubble Space Telescope, revealed an abundance of helium in the upper atmosphere of the exoplanet, which was only discovered in 2017, according to the study published in the journal Nature. David Sing, co-author of the study also from the University of Exeter, concludes: “Our new method, along with future telescopes such as the NASA/ESA/CSA James Webb Space Telescope, will allow us to analyse atmospheres of exoplanets in far greater detail than ever before.”

[1] The measurement of an exoplanet’s atmosphere is performed when the planet passes in front of its host star. If smaller, Earth-sized planets have similar helium clouds, this new technique offers an exciting means to study their upper atmospheres in the very near future.."

Helium was first detected as an unknown yellow spectral line signature in sunlight in 1868. The signal of the gas, according to a release from the University, was so massive that the scientists now believe the upper atmosphere of WASP-107b could be going up to thousands of kilometers into space. Till now, notes a report by Space.com, the hunt for exoplanets has only involved looking for hydrogen in their atmospheres which is not only the most abundant element in the universe, it also makes up most of the gas giants in the Solar System like Jupiter. We know there is helium in the Earth’s upper atmosphere and this new technique may help us to detect atmospheres around Earth-sized exoplanets – which is very difficult with current technology.”

WASP-107b is one of the lowest density planets known: While the planet is about the same size as Jupiter, it has only 12% of Jupiter’s mass. “By measuring infrared light, we can see further out into space than if we were using ultraviolet light.”

Orbiting its host star every six days, WASP-107b has one of the chilliest atmospheres of any known exoplanet. WASP-107b was observed by the Hubble Space Telescope, pictured above by the crew of the shuttle Atlantis during its final servicing mission NASA

The researchers employed a new technique to analyse the data, which measured the infrared properties of the atmospheric light to detect helium that existed in an excited state. “The strong signal from helium we measured demonstrates a new technique to study upper layers of exoplanet atmospheres in a wider range of planets,” says Spake “Current methods, which use ultraviolet light, are limited to the closest exoplanets. The team behind the discovery used the observational prowess of the venerable Hubble Space Telescope to probe WASP-107b, measuring the spectrum of light that had passed through the upper reaches of the exoplanet's atmosphere.
Helium has been detected for the first time in the atmosphere of an exoplanet by scientists observing WASP-107b.