A recent study conducted by researchers at the University of Bristol in the UK, using data obtained from the James Webb Space Telescope’s Mid-Infrared Instrument (MIRI), has revealed the presence of quartz nanocrystals in the upper atmosphere of WASP-17 b. This exoplanet, located approximately 1,324 light-years from Earth, has been classified as a “puffy” hot Jupiter due to its unique orbital period and extreme temperatures. The discovery of quartz nanocrystals in an exoplanet’s atmosphere is an unexpected breakthrough that could provide valuable insights into the formation and evolution of exoplanetary clouds and atmospheres.
Astronomers involved in the study express their excitement over the surprising find. Dr. David Grant, the lead author of the study, states, “We were thrilled! We knew from previous observations that there were aerosols in WASP-17 b’s atmosphere, but we didn’t expect them to be made of quartz.” This discovery deviates from the traditional observation of magnesium-rich silicates in exoplanetary atmospheres, shedding light on new possibilities for cloud composition and atmospheric evolution.
While the quartz crystals found in WASP-17 b’s atmosphere resemble those found on Earth in terms of shape, their size is significantly different. These crystals are tiny, measuring only 10 nanometers in diameter, which is one-millionth of a centimeter. In comparison, the average quartz crystal on Earth can reach a few centimeters in diameter. These extraordinary crystals raise questions about their formation in the extreme conditions of WASP-17 b’s atmosphere.
The extreme heat of approximately 1,500 degrees Celsius (2,700 °F) and the low pressure in the upper atmosphere of WASP-17 b create the ideal conditions for the direct formation of solid crystals from gas. Unlike Earth, where crystals usually form through a liquid phase, the absence of a liquid phase in the exoplanet’s atmosphere allows for the direct conversion of gas into solid structures. This phenomenon challenges our understanding of crystal formation and highlights the unique nature of exoplanetary atmospheres.
WASP-17 b, discovered in 2009, stands out from other exoplanets due to its retrograde orbit, meaning it orbits in the opposite direction of its star’s rotation. Previous studies have identified the presence of water and sodium in its atmosphere. Despite the identification of quartz in this recent study, the exoplanet’s atmospheric composition aligns with that of traditional gas giant planets, primarily composed of hydrogen and helium. WASP-17 b is also tidally locked with its parent star, resulting in one side constantly facing the star. This unique characteristic leads to the vaporization of clouds on the dayside, making it challenging for astronomers to determine the amount of quartz in the atmosphere and the activity of the clouds.
The study of quartz nanocrystals in WASP-17 b’s atmosphere is part of the larger effort known as the Deep Reconnaissance of Exoplanet Atmospheres using Multi-instrument Spectroscopy (DREAMS) conducted by the JWST-Telescope Scientist Team. By conducting in-depth analyses of exoplanets representing different classes, researchers aim to gain a deeper understanding of the formation and evolution of exoplanetary atmospheres. The findings from these studies, including the discovery of quartz nanocrystals, will contribute to our knowledge of exoplanets and their diverse atmospheres.
The unexpected presence of quartz nanocrystals in the upper atmosphere of WASP-17 b opens up new possibilities for understanding exoplanetary clouds and atmospheres. This discovery challenges previous assumptions regarding the composition of exoplanetary aerosols and highlights the unique conditions that can lead to the formation of quartz crystals. As scientists continue to explore exoplanets and their atmospheres, they must remain open to unexpected findings that can reshape our understanding of the universe. The study of exoplanets, such as WASP-17 b, will undoubtedly contribute to future breakthroughs in astrophysics and deepen our understanding of the vast expanse beyond Earth’s boundaries.