Article image

Rare "glory lights" rainbow effect seen on an exoplanet for the first time, baffling scientists

In the vast expanse of the universe, countless exoplanets orbit distant stars, each with its unique characteristics and mysteries. Recent data from various space missions suggest that the exoplanet WASP-76b may hold the first extrasolar “glory lights” effect ever observed.

Peculiar conditions of WASP-76b

Olivier Demangeon, an astronomer at the Instituto de Astrofísica e Ciências do Espaço in Portugal and the lead author of the study, explains the rarity of this phenomenon.

“There’s a reason no glory has been seen before outside our Solar System — it requires very peculiar conditions,” Demangeon explained.

“First, you need atmospheric particles that are close-to-perfectly spherical, completely uniform and stable enough to be observed over a long time. The planet’s nearby star needs to shine directly at it, with the observer – here Cheops – at just the right orientation,” he noted.

Significance of glory lights effect on an exoplanet

The first glory lights effect on a planet other than Earth was seen on Venus in 2011 by the Venus Express Orbiter. The glory in the images here was seen at the Venus cloud tops, 70 km above the planet’s surface. It is 1200 km wide as seen from the spacecraft, 6000 km away.

If confirmed, the first exoplanetary glory lights would provide valuable insights into the planet and its host star. ESA Research Fellow Matthew Standing emphasizes the incredible scale of the observation, saying, “What’s important to keep in mind is the incredible scale of what we’re witnessing.”

He continued, “WASP-76b is several hundred light-years away – an intensely hot gas giant planet where it likely rains molten iron. Despite the chaos, it looks like we’ve detected the potential signs of a glory. It’s an incredibly faint signal.”

Hellish landscape of WASP-76b

WASP-76b, an ultra-hot Jupiter-like planet, has been the subject of intense scrutiny since its discovery in 2013.

The exoplanet is locked in a tight orbit around its host star, with one side permanently facing the scorching heat.

Temperatures on this side reach a staggering 2400 degrees Celsius, causing elements that would form rocks on Earth to melt and evaporate.

These elements then condense on the slightly cooler night side, creating iron clouds that rain molten iron.

Unexpected effect of glory lights glow

Scientists have been intrigued by an apparent asymmetry in WASP-76b’s outermost regions, or ‘limbs,’ as it passes in front of its host star.

Data from various ESA and NASA missions, including TESS, Hubble, and Spitzer, were analyzed in this revealing study.

However, it was the collaboration between ESA’s Cheops and NASA’s TESS that provided the first hints of the glory phenomenon.

Olivier Demangeon explains the significance of the discovery. “This is the first time that such a sharp change has been detected in the brightness of an exoplanet, its ‘phase curve.’ This discovery leads us to hypothesize that this unexpected glow could be caused by a strong, localized and anisotropic (directionally dependent) reflection – the glory effect.”

Understanding the glory lights effect

While the glory effect creates rainbow-like patterns, it differs from rainbows in its formation. Rainbows form when sunlight passes through media with different densities, causing the light to bend and split into various colors.

In contrast, glory occurs when light passes between narrow openings, such as water droplets in clouds or fog, resulting in concentric rings of color due to the diffraction and interference of light waves.

Implications for habitability

Confirmation of the glory effect on WASP-76b would indicate the presence of clouds composed of perfectly spherical droplets that have persisted for at least three years or are being continuously replenished. The atmosphere’s temperature would also need to be stable over time for such clouds to exist.

Theresa Lüftinger, Project Scientist for ESA’s upcoming Ariel mission, emphasizes the importance of detecting such minute wonders.

“Being able to detect such minute wonders so far away will teach scientists and engineers how to detect other hard-to-see but critical phenomena. For example, sunlight reflecting off liquid lakes and oceans – a requirement for habitability,” she explained.

Need for further observations

While the evidence for the glory effect on WASP-76b is compelling, further observations are needed to confirm its presence conclusively.

Follow-up observations from the NIRSPEC instrument onboard the NASA/ESA/CSA James Webb Space Telescope or ESA’s upcoming Ariel mission could provide the necessary proof.

The possibility of discovering more gloriously revealing colors shining from other exoplanets is an exciting prospect for astronomers.

Glory lights effect and our understanding of the universe

The potential discovery of the first extrasolar glory on WASP-76b is a testament to the power of international collaboration and the capabilities of modern space missions.

As Olivier Demangeon reflects on the journey that led to this discovery, he shares the satisfaction that comes with persevering in the face of uncertainty.

“It has taken some time to get here, with moments where I asked myself – ‘Why are you insisting on this? It might be better to do something else with your time.’ But when this feature appeared out of the data, it was such a special feeling – a particular satisfaction that doesn’t happen every day,” Demangeon concluded.

A glimpse of glory

In summary, as astronomers continue to unravel the mysteries of exoplanet WASP-76b, the potential discovery of the first extrasolar glory lights effect serves as a testament to the power of international collaboration and the capabilities of modern space missions.

This finding deepens our understanding of the incredible beauty and complexity that exists beyond our own planet and poses exciting new questions about the potential for life in the cosmos.

With each new observation and revelation, we inch closer to answering the fundamental questions that have captivated humanity for centuries, reminding us of the boundless wonders that await us in the vast expanse of the universe.

The full study was published in the journal Astronomy & Astrophysics.


Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and


News coming your way
The biggest news about our planet delivered to you each day