A recent research published in The Astrophysical Journal Letters has revealed a fascinating discovery in the realm of exoplanets. Using data obtained by the James Webb Space Telescope’s (JWST) Mid-Infrared Instrument (MIRI), a team of astronomers identified the presence of quartz nanocrystals in the upper atmosphere of WASP-17 b. This exoplanet, located approximately 1,324 light-years from Earth, is an intriguing celestial body classified as a “puffy” hot Jupiter due to its short orbital period and extreme temperatures. While the existence of aerosols in its atmosphere was already known, the revelation that these aerosols are made of quartz was unexpected and has significant implications for our understanding of exoplanetary atmospheres.
The discovery of quartz nanocrystals in the atmosphere of WASP-17 b challenges the conventional belief that exoplanets primarily possess magnesium-rich silicates like pyroxene or olivine. The use of JWST’s MIRI instrument provided a novel perspective on the composition of exoplanetary clouds and atmospheres. This finding opens up new avenues of research into the formation and evolution of exoplanet clouds, as well as their distinct atmospheric characteristics.
One remarkable aspect of the quartz nanocrystals found in WASP-17 b’s atmosphere is their size. Unlike terrestrial quartz crystals, which can range from a few centimeters to meters in diameter, the nanocrystals detected are only 10 nanometers in size. This significant disparity in size raises questions about the unique conditions that allow such tiny crystals to form. The extreme heat of the exoplanet, reaching temperatures of around 1,500 degrees Celsius, ensures that solid crystals can form directly from gases without transitioning through a liquid phase. Additionally, the low atmospheric pressure on WASP-17 b, approximately one-thousandth of Earth’s surface pressure, contributes to the formation of these nanocrystals.
Discovered in 2009, WASP-17 b has captivated astronomers with its intriguing characteristics. It is the first exoplanet known to have a retrograde orbit, making it unique among its counterparts. The presence of water and sodium in its atmosphere has been previously identified, emphasizing its similarity to traditional gas giant planets. However, WASP-17 b stands out due to its relatively low mass compared to Jupiter, while boasting a size seven times greater. This makes it one of the puffiest exoplanets ever discovered. Furthermore, the planet is tidally locked with its parent star, resulting in a perpetual day-night divide. As the clouds encircle the planet, they are vaporized on the dayside, leading to complex dynamics that scientists are still striving to comprehend fully.
While the recent study uncovered the presence of quartz nanocrystals in the atmosphere of WASP-17 b, there is much to learn about the activity of the planet’s clouds and the exact quantity of quartz present. Astronomers speculate that the clouds are likely concentrated along the day-to-night transition region, known as the terminator, which is where the observation data was collected. The powerful winds on the exoplanet, potentially moving at speeds of thousands of miles per hour, could play a significant role in distributing these delicate glassy particles.
The analysis of quartz nanocrystals in WASP-17 b’s atmosphere forms part of a broader investigation known as the Deep Reconnaissance of Exoplanet Atmospheres using Multi-instrument Spectroscopy (DREAMS). This extensive initiative, conducted by the JWST-Telescope Scientist Team, aims to conduct in-depth analyses of exoplanets across different classes. The DREAMS project comprises a temperate terrestrial planet, a warm Neptune, and the hot Jupiter WASP-17 b. The findings from the study of these diverse exoplanets will provide invaluable insights into the intricate processes governing the formation and evolution of exoplanetary atmospheres.
The discovery of quartz nanocrystals in the upper atmosphere of WASP-17 b is an exciting development in the field of exoplanet research. This unexpected finding challenges existing assumptions about the composition of exoplanetary aerosols and could revolutionize our understanding of exoplanetary atmospheres. As astronomers delve deeper into the mysteries of exoplanets, the study of unique celestial bodies like WASP-17 b opens up a world of possibilities for future discoveries. By continually pushing the boundaries of our knowledge, scientists pave the way for further advancements and propel humanity’s understanding of the universe. So, let us embrace these surprises and continue our scientific exploration, always looking up to the skies.