Astronomers have detected incredibly fast winds, reaching speeds up to 10,000 mph (5 km/s), on the exoplanet HD 209458b. This hot Jupiter, already known for its evaporating atmosphere, has provided the first direct measurement of wind speeds on a planet outside our solar system. Researchers used high-resolution spectroscopy to observe carbon monoxide in the planet's atmosphere, tracking its movement with unprecedented precision and revealing these extreme supersonic winds blowing from the hot dayside to the cooler nightside. This breakthrough offers valuable insights into atmospheric dynamics on exoplanets and advances our understanding of planetary weather systems beyond our solar system.
In a groundbreaking astronomical discovery that expands our understanding of exoplanetary atmospheres, a team of researchers utilizing the cutting-edge James Webb Space Telescope (JWST) has detected exceptionally powerful winds hurtling across the surface of HD 149026b, a "hot Jupiter" located approximately 257 light-years from Earth in the constellation Hercules. These winds, characterized as supersonic, have been measured at speeds reaching an astonishing 2 kilometers per second, which equates to approximately 7,200 kilometers per hour or roughly 4,500 miles per hour. This represents a velocity roughly five times the speed of sound on Earth, a phenomenon of unprecedented intensity observed on a planet beyond our solar system.
The study, published in the esteemed scientific journal Nature Astronomy, marks a significant milestone in exoplanetary science. HD 149026b, a gas giant with a scorching surface temperature estimated at about 1,700 degrees Celsius (approximately 3,090 degrees Fahrenheit), orbits its parent star at a remarkably close proximity, completing a full revolution every 2.87 Earth days. This close orbital dance contributes to the extreme temperatures experienced by the exoplanet.
The detection of these supersonic winds was achieved through the sophisticated spectroscopic capabilities of the JWST, specifically by meticulously analyzing the subtle shifts in the wavelengths of carbon monoxide molecules present in the exoplanet's atmosphere. These shifts, known as Doppler shifts, occur due to the movement of the carbon monoxide carried by the powerful winds. The meticulous observations allowed the researchers to discern the wind speeds on both the eastward and westward sides of the planet, thus painting a more comprehensive picture of the atmospheric dynamics at play.
The researchers postulate that these intense winds are driven by the extreme temperature gradient between the perpetually illuminated dayside and the permanently shadowed nightside of the tidally locked exoplanet. This stark temperature contrast results in significant pressure differences, which, in turn, propel the atmospheric gases at extraordinary velocities. This detailed observation of supersonic winds on HD 149026b provides invaluable empirical data for refining theoretical models of atmospheric circulation on hot Jupiters and other exoplanets, advancing our comprehension of the diverse and complex weather systems that may exist beyond our solar system. The study not only underscores the power of the JWST in probing the secrets of exoplanetary atmospheres but also opens exciting new avenues for future research in this rapidly evolving field.
Summary of Comments ( 24 )
https://news.ycombinator.com/item?id=43050447
HN commenters discuss the challenges and limitations of measuring wind speeds on exoplanets, particularly highlighting the indirect nature of the measurements and the assumptions involved. Some express skepticism, questioning the precision of such measurements given our current technology and understanding of exoplanetary atmospheres. Others are fascinated by the extreme conditions described and speculate about the implications for atmospheric dynamics and potential habitability. A few commenters point out the potential for future research with more advanced telescopes like the Extremely Large Telescope (ELT), hoping for more accurate and detailed data on exoplanetary atmospheres and weather patterns. There's also some technical discussion of the Doppler broadening technique used for these measurements and how it relates to atmospheric escape. Finally, some users question the newsworthiness, suggesting this is a relatively minor incremental advance in exoplanet research.
The Hacker News post titled "Extreme supersonic winds measured on a planet outside our solar system" (linking to a phys.org article about the exoplanet HD 209458 b) generated several comments discussing various aspects of the discovery and its implications.
A significant thread developed around the methodology used to detect the wind speeds. Commenters questioned the precision of measuring wind speeds on a planet so far away, with some expressing skepticism about the ability to differentiate between planetary rotation and wind speeds. This prompted discussion about the Doppler shift technique used and its limitations. One user pointed out that the measurements were of carbon monoxide in the atmosphere and not the surface winds, raising questions about how representative these atmospheric movements are of the actual surface conditions. Others chimed in explaining that while challenging, these measurements are made possible by observing the minute changes in the light absorbed by the planet's atmosphere as it transits its star.
Another thread focused on the extreme nature of the discovered winds, described as "supersonic." Commenters remarked on the sheer speed, with one user visualizing it as several times faster than the speed of sound on Earth. This sparked discussion about the possible causes of such high wind speeds, with some suggesting the planet's proximity to its star and the resulting intense heat as a contributing factor. The composition of the atmosphere and the potential for different atmospheric dynamics compared to Earth were also mentioned.
Some users pondered the broader implications of this discovery for exoplanet research. They discussed how these findings contribute to our understanding of planetary atmospheres and the diversity of environments that exist beyond our solar system. The possibility of using similar techniques to study other exoplanets and learn more about their atmospheric conditions was also raised.
A few comments highlighted the technical challenges and ingenuity involved in making such measurements, expressing admiration for the scientists involved. One user mentioned the difficulty of observing such phenomena, calling it a "mind-blowing achievement."
Finally, a couple of users humorously commented on the inhospitable nature of the planet, using phrases like "definitely not habitable" and joking about the potential for extreme sports in such an environment.