The James Webb Space Telescope (JWST) has provided new clues about how the ultra-hot exoplanet WASP-121b was formed and where it might have originated in the disc of gas and dust around its star. The detection of multiple key molecules, including water vapour, carbon monoxide, silicon monoxide, and methane, has allowed a team of astronomers to compile an inventory of the carbon, oxygen, and silicon in the atmosphere of WASP-121b.

The ultra-hot giant planet orbits its host star at a distance only about twice the star’s diameter, completing one orbit in approximately 30.5 hours. The planet exhibits two distinct hemispheres: one that always faces the host star, with temperatures locally exceeding 3000 degrees Celsius, and an eternal nightside where temperatures drop to 1500 degrees.

The team led by astronomers Thomas Evans-Soma and Cyril Gapp was able to compile an inventory of the carbon, oxygen, and silicon in the atmosphere of WASP-121b. The detection of these molecules suggests that the planet’s atmosphere is rich in gases that are stable at high temperatures.

However, the team’s observations also revealed a surprise: the abundance of methane on the nightside of the exoplanet was much higher than expected. To explain this result, the team proposes that methane gas must be rapidly replenished on the nightside to maintain its high abundance. A plausible mechanism for doing this involves strong vertical currents lifting methane gas from lower atmospheric layers.

The JWST’s Near-Infrared Spectrograph (NIRSpec) was used to observe WASP-121b throughout its complete orbit around its host star. As the planet rotates on its axis, the heat radiation received from its surface varies, exposing different portions of its irradiated atmosphere to the telescope. This allowed the team to characterize the conditions and chemical composition of the planet’s dayside and nightside.

The astronomers also captured observations as the planet transited in front of its star. During this phase, some starlight filters through the planet’s atmospheric limb, leaving spectral fingerprints that reveal its chemical makeup. The emerging transmission spectrum confirmed the detections of silicon monoxide, carbon monoxide, and water that were made with the emission data.

The MPIA scientists involved in this study included Thomas M. Evans-Soma (also at the University of Newcastle, Australia), Cyril Gapp (also at Heidelberg University), Eva-Maria Ahrer, Duncan A. Christie, Djemma Ruseva (also at the University of St Andrews, UK), and Laura Kreidberg.

Other researchers included David K. Sing (Johns Hopkins University, Baltimore, USA), Joanna K. Barstow (The Open University, Milton Keynes, UK), Anjali A. A. Piette (University of Birmingham, UK and Carnegie Institution for Science, Washington, USA), Jake Taylor (University of Oxford, UK), Joshua D. Lothringer (Space Telescope Science Institute, Baltimore, USA and Utah Valley University, Orem, USA), and Jayesh M. Goyal (National Institute of Science Education and Research (NISER), Odisha, India).

The JWST’s role in the discovery was crucial, as it allowed the team to observe WASP-121b throughout its complete orbit around its host star, capturing a wealth of information about the exoplanet’s atmosphere and composition.

In conclusion, the study provides new insights into the formation and evolution of ultra-hot exoplanets like WASP-121b. The detection of methane on the nightside of the exoplanet challenges current dynamical models of exoplanetary atmospheres, suggesting that these models will need to be adapted to reproduce the strong vertical mixing observed in this study.

The discovery of an object called ASKAP J1832-0911 has left astronomers puzzled. This mysterious entity emits pulses of radio waves and X-rays for two minutes every 44 minutes. What makes this finding even more intriguing is that it’s the first time such an object, known as a long-period transient (LPT), has been detected in X-rays.

The team behind this discovery used the ASKAP radio telescope to detect the radio signals, which they then correlated with X-ray pulses detected by NASA’s Chandra X-ray Observatory. This coincidence of observations allowed them to confirm that ASKAP J1832-0911 is indeed emitting both types of radiation.

LPTs are a relatively recent discovery, with only ten such objects found so far. Scientists still have no clear explanation for what causes these signals or why they ‘switch on’ and ‘switch off’ at such long, regular intervals. Some theories suggest that ASKAP J1832-0911 could be a magnetar or a pair of stars in a binary system with one star being a highly magnetised white dwarf.

However, even these theories don’t fully explain what’s being observed. This discovery might indicate the existence of new types of physics or models of stellar evolution. By detecting objects like ASKAP J1832-0911 using both X-rays and radio waves, scientists hope to find more examples and gain a better understanding of their nature.

The discovery of ASKAP J1832-0911 is not only significant for the scientific community but also showcases an incredible teamwork effort between researchers across the globe. The study’s findings have been published in Nature, and the object itself is located in our Milky Way galaxy about 15,000 light-years from Earth.

The discovery of ongoing surface modification on Jupiter’s moon Europa has been made possible by recent experiments conducted by Southwest Research Institute’s Dr. Ujjwal Raut and his team. Analyzing spectral data collected by the James Webb Space Telescope (JWST), they found evidence that Europa’s icy surface is constantly changing, with crystalline ice forming at different rates in various areas.

On Earth, water ice forms a crystalline structure when water molecules arrange into a hexagonal pattern during freezing. However, on Europa’s surface, exposed water ice is bombarded by charged particles from space, disrupting the crystalline structure and creating amorphous ice. The experiments conducted by Dr. Raut’s team demonstrated that this process occurs rapidly in some areas of Europa’s surface.

The combination of JWST data and laboratory results reveals a complex interplay between external processes and geologic activity affecting the surface. Researchers have long believed that Europa’s surface is covered by a thin layer of amorphous ice, protecting crystalline ice beneath. However, this new study found crystalline ice on the surface as well as at depth in certain areas, particularly in the Tara Regio region.

“We think that the surface is fairly porous and warm enough in some areas to allow the ice to recrystallize rapidly,” said Dr. Richard Cartwright, lead author of the paper and a spectroscopist at Johns Hopkins University’s Applied Physics Laboratory. “Also, in this same region, generally referred to as a chaos region, we see a lot of other unusual things, including the best evidence for sodium chloride, like table salt, probably originating from its interior ocean.”

The presence of CO2 and hydrogen peroxide on Europa’s surface is another striking feature of this study. These chemicals are believed to originate from the moon’s subsurface ocean, nearly 20 miles (30 kilometers) beneath its icy shell.

“Our data showed strong indications that what we are seeing must be sourced from the interior, perhaps from a subsurface ocean,” said Dr. Raut. “This region of fractured surface materials could point to geologic processes pushing subsurface materials up from below.”

The findings of this study have significant implications for our understanding of Europa’s surface and its potential habitability. The presence of liquid water beneath the ice, along with other substances like CO2 and hydrogen peroxide, suggests that life may be present on this moon, making it an exciting destination for future exploration.