in News
A scorching Jupiter-like planet exhibits extreme winds that are being influenced and moderated by its magnetic field.(Image credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick)Share this article 0Join the conversationFollow usAdd us as a preferred source on GoogleSubscribe to our newsletter
In a groundbreaking discovery, researchers assert they have directly quantified the magnetic fields of multiple celestial bodies outside our solar system—potentially introducing a vital instrument in the quest for life-supporting planets and extraterrestrial organisms.
Magnetic fields play a critical role in planetary atmospheres, consequently affecting their ultimate destinies and potential for habitability. It is known, for instance, that Earth’s magnetic field has consistently shielded our planet from detrimental radiation, enabling our world to evolve into a vibrant, verdant sphere while the inert planet Mars has become desolate and seemingly lifeless.
The significance of a protective magnetosphere is undeniable. However, the magnetic fields of exoplanets, or alien worlds orbiting stars beyond our solar system, have remained poorly defined, until this present moment.
In a research paper published Tuesday (June 2) in the esteemed journal Nature Astronomy, a vast, international consortium of scientists surveyed seven intensely hot planets and discovered that their atmospheric currents were slower than anticipated, suggesting that magnetic fields were exerting a decelerating influence.
“This pivotal advancement unlocks an entirely new avenue for exoplanet investigation,” stated study co-author Julia Seidel, an astronomer affiliated with the Lagrange Laboratory in Nice, France, in a press release. “This marks the inaugural instance where we can compare the magnetic conditions of other worlds—a crucial progression toward ultimately discerning which planets can sustain life, retain their water, and perhaps even, in the future, harbor life as we comprehend it.”
Unexpected astronomy
The investigators were not specifically aiming to detect exoplanetary magnetic fields. Rather, their objective was to ascertain if atmospheric currents across the universe exhibit similar behavior on extremely hot planets.
Consequently, they concentrated their efforts on seven “ultra-hot Jupiters,” which are blazing gas giants orbiting so near their parent stars that they are tidally locked—presenting one hemisphere perpetually towards the star and the other in constant shadow.
Under such extreme stellar radiation, these seven planets achieve estimated equilibrium temperatures of approximately 2,600 Kelvin (exceeding 4,200 degrees Fahrenheit), generating formidable winds ranging from nearly 4,500 miles (7,200 kilometers) per hour to almost 16,000 mph (25,000 kmh). For comparative purposes, our own less scorching Jupiter only achieves relatively modest wind speeds of 900 mph (1,500 kmh).
The scientists measured these extraterrestrial wind velocities utilizing the ESPRESSO instrument aboard the European Southern Observatory’s Very Large Telescope in Chile and the MAROON-X instrument on the Gemini North telescope located in Hawaii.
An artistic depiction illustrating a hot Jupiter exoplanet in close proximity and tidally locked to its host star. Its magnetic field, visualized in blue, serves to decrease the otherwise rapid winds transitioning from its day side to its night side.
(Image credit: ESO/M. Kornmesser/L. Calçada))
These instruments are spectrographs, designed to dissect the light from a celestial object into its component wavelengths, thereby revealing its atmospheric makeup. Consequently, these observations enabled the astronomers to gauge wind speeds by tracking the movement of iron within the atmospheres of these exoplanets.
A counterintuitive discovery
In the process, they uncovered several unexpected findings. Primarily, wind speeds on these heated, gaseous planets actually diminished as temperature increased—the hotter the planet, the slower the wind speed.
“This is entirely contrary to expectations because, all other factors being equal, hotter planets possess more energy to accelerate the winds,” explained study co-author Vivien Parmentier, an astronomer and professor at the Lagrange Laboratory, in a separate statement. “Something must be occurring that reduces wind speeds for warmer objects.”
Related stories
- Scientists identify 10,000 ‘impossible’ exoplanet candidates, potentially tripling the number of known alien worlds
- Science history: Astronomers spot first known planet around a sunlike star, raising hopes for extraterrestrial life — Nov. 1, 1995
- Scientists tracked faint signals from the stars — and may have turned up hundreds of undiscovered planets
The researchers inferred that the magnetic fields might be responsible for applying the “brakes” to these winds, by impeding the motion of electrically charged particles within the atmospheres of these exoplanets.
Perhaps surprisingly, the investigation suggests that these magnetic fields possess a strength of only several gauss—instead of hundreds of gauss, as hypothesized by some theoretical models. Such magnitudes are comparable to those of the significantly cooler gas giants within our solar system. This finding could therefore also assist in harmonizing predictive models for planetary magnetic fields.
In summary, this seminal study may establish the benchmark for detecting magnetic fields surrounding planets beyond our own. Applying this methodology to other celestial bodies could inform future explorations for potentially habitable worlds, an endlessly captivating prospect as next-generation instruments begin to direct their observational capabilities towards other potential Earth-like planets across the cosmos.
Sourse: www.livescience.com
