Epic Journey to Hell Planet: Weber reveals how this giant migrates from ice to fire

Now, an ultra-hot exoplanet may form a car around its star within 30 hours before undergoing an epic migration.

New observations from the James Webb Space Telescope reveal an atmospheric fingerprint of the formation story that unlocks Wasp-121b, suggesting that it originates from conditions similar to Jupiter and Saturn formed in our solar system.

The planet exhibits extreme temperature differences between day and night, over 3,000°C, facing stars at eternal nighttimes with a relatively cool 1,500°C. This temperature contrast allows researchers to detect different molecules throughout the Earth’s hemisphere, providing unprecedented insights into how giant planets accumulate their atmosphere.

Chemical detective work reveals the history of formation

Using Weber’s powerful infrared vision, astronomers detected water vapor, carbon monoxide, silicon monoxide and methane in the atmosphere of Wasp-121b. The specific combination and abundance of these molecules tells a fascinating formation story.

The team found that WASP-121B’s atmosphere contains super-strong carbon, oxygen and silicon compared to its host star. Most notably, the Earth’s carbon-to-oxygen ratio is 0.92, almost twice the size of its stars.

The chemical signature suggests that a planet formed in a region cold enough to freeze the water, but warm enough that methane can remain gaseous. The study notes: “In our own solar system, this region is located between the orbits of Jupiter and Uranus.” This suggests that Wasp 121b has undergone a large-scale migration from these external regions to the current orbit of hell.

Key atmospheric discoveries:

• Silicon monoxide was detected at 5.7-6.2σ confidence
• The ratio of carbon to oxygen is 1.63 times higher than that of the host star
• Methane is found only at night
• Evidence of mass fusion of approximately 21 rock materials

Unexpected methane discovery challenge model

The discovery of methane at night on WASP-121B is a major surprise. Current atmospheric models predict that gas should circulate from inflammatory days to nighttime compared to chemical compositions, which can adapt to temperature changes. In this case, methane should be free of both hemispheres.

Instead, astronomers found abundant methane only at night, suggesting that a powerful vertical mixing process is rapidly lifting methane-rich gases from deeper atmospheres. This discovery challenges existing models of ultra-hot planetary atmospheres.

Unexpected methane abundance is also related to the history of the formation of the earth. During formation, WASP-121b appeared to open a gap on its original menstrual disk that blocked the inward flow of water ice pebbles while continuing to evaporate methane pebbles to a gas rich in carbon.

Silicon tells the story of rock bombing

Silicon monoxide detection results proved particularly important because it showed that the planet fused a large amount of rock material after forming a gaseous envelope. The researchers calculated that the Earth’s mass of about 21 rock materials, similar to an asteroid or planet, accumulates and mixes throughout the atmosphere.

The bombing of this rock occurred later in the planet’s development, after the Earth had grown up to capture its huge gaseous atmosphere. The enhancement of silicon shows that pebble accumulation and planetary bombing play a crucial role in shaping the composition of giant planets.

A key finding often overlooked in formation studies: the team found that the volatility ratio of WASP-121b remained below certain thresholds to distinguish different stratigraphic pathways. Specifically, the (C+O)/Si ratio of the planet remains below 5.24 times the stellar value, indicating that the accumulation of rock material is still significant even after the formation of a gaseous envelope.

Advanced Observatory enables global view

Weber’s near-infrared spectrometer continuously observed WASP-121B for 37.8 hours, capturing heat emission as the planet completes its orbit. The technology is called phase curve observation, which allows researchers to map temperature and chemical changes across the entire Earth’s surface.

These observations include two secondary solar eclipses and a major transit, providing coverage for the diurnal hemisphere. Data quality can detect relatively weak spectral characteristics that were previously unreliable to measure by instruments.

Traditional ground telescopes have been working to detect volatile and refractory species simultaneously, as their strongest spectral features appear at different wavelengths. Weber’s extensive infrared coverage ultimately makes for a comprehensive atmospheric inventory of superheated planets.

Influence on planet formation theory

These findings support models in which giant planets are formed through process combinations rather than single mechanisms. WASP-121b appears to accumulate most of the volatiles by evaporating the accumulation of gases rich in pebbles, and later incorporated a large amount of rock material through planetary bombing.

The Earth’s superstable element ratio shows that it forms outside the water ice line, and solid particles can survive long enough to drift inward and enrich the surrounding gases. However, a specific carbon-to-oxygen ratio indicates formation occurs in the methane ice line, where the carbon compound remains in the gaseous state.

What makes this discovery particularly interesting is how it is associated with the formation environment of Jupiter and Saturn. Like WASP-121B, these giants may have formed in areas where water is frozen but carbon compounds are still available, allowing them to create a large atmosphere rich in heavy elements.

The study shows how Weber’s ability is revolutionary by enabling detailed atmospheric archaeology. By reading about chemical characteristics preserved in planetary atmospheres, astronomers can reconstruct the history of formation spanning the ancient solar system over millions of years.