Swiss space telescope observes exoplanet ‘rainbow’
The Swiss space telescope CHEOPS has found a type of rainbow on a planet 637 light years away. The observation of a so-called “glory” is likely the first evidence of this phenomenon outside our solar system.
However, further investigations are needed to confirm whether the observation on the planet known as “WASP-76b” truly was a glory, the University of Geneva, which runs scientific operations for CHEOPS, announced on Friday. The researchers presented their discovery in a study in the journal Astronomy & Astrophysics.
A glory is a rainbow-like scattering of light that looks like a halo. It occurs when light is reflected as it passes through a cloud of perfectly uniform droplets. In the case of Earth, these droplets are made of water.
More
In space exploration, Switzerland punches above its weight
Drops of iron?
However, the nature of these droplets on WASP-76b is still a mystery, according to the university. They could be made of iron, as this element has already been detected on the surface of the planet.
“The reason why such a glow has never been observed outside our solar system is that this phenomenon requires very specific conditions,” explained first author Olivier Demangeon in the press release. “First of all, the atmospheric particles must be almost perfectly spherical, completely uniform and sufficiently stable to be observed throughout a long time. These droplets have to be directly illuminated by the planet’s host star, and the observer – in this case CHEOPS – must be in the right position.”
The discovery of such tiny phenomena at such a great distance will enable scientists to recognise other equally important phenomena, according to the University of Geneva. For example, the reflection of starlight on liquid lakes and oceans, which is a necessary condition for habitability.
More
CHEOPS exoplanet search extended for another three years
2,400 degrees Celsius
WASP-76b has been closely scrutinised by astronomers since its discovery in 2013. Examinations have revealed that the gas giant is characterised by extreme conditions, with iron rain and temperatures of up to 2,400°C. Chemical elements that would form rocks on Earth melt and vaporise there, before condensing on the slightly cooler night side and forming clouds.
Adapted from German by DeepL/kc/ts
This news story has been written and carefully fact-checked by an external editorial team. At SWI swissinfo.ch we select the most relevant news for an international audience and use automatic translation tools such as DeepL to translate it into English. Providing you with automatically translated news gives us the time to write more in-depth articles.
If you want to know more about how we work, have a look here, and if you have feedback on this news story please write to english@swissinfo.ch.
In compliance with the JTI standards
More: SWI swissinfo.ch certified by the Journalism Trust Initiative
You can find an overview of ongoing debates with our journalists here. Please join us!
If you want to start a conversation about a topic raised in this article or want to report factual errors, email us at english@swissinfo.ch.