Astronomers utilizing the James Webb Space Telescope (JWST) have revisited the far reaches of our solar system, revealing that Pluto is surpassing expectations.
When NASA’s New Horizons spacecraft flew by Pluto in 2015, it was classified as a Dwarf Planet, showcasing itself as a frozen sphere adorned with icy plains and rugged peaks. However, one of the most astonishing discoveries was its bluish multi-layered haze, which blankets the dwarf planet’s sky, extending over 185 miles (300 kilometers) above the surface. This haze is more complex and reaches higher altitudes than scientists had originally anticipated.
Nearly a decade later, fresh data from JWST confirms that Pluto’s haze is not just an intriguing visual phenomenon, but it also influences the climate of the dwarf planet.
“This is unique in the solar system,” stated Tanguy Bertrand, an astronomer at the Paris Observatory in France who spearheaded the analysis, in an interview with Live Science. “It represents a new type of climate.”
These findings, detailed in a study published on June 2nd in Natural Astronomy, indicate that similar processes may exist on other hazy worlds within our solar system, potentially offering insights into the early climate of our own planet.
Lift the Haze
Pluto’s elevated haze consists of intricate organic molecules generated by sunlight-driven reactions between methane and nitrogen. The hypothesis that this haze could impact Pluto’s climate was first proposed in 2017. Computer models indicated that these particles absorb sunlight during the day, radiating infrared energy into space at night, thus cooling the atmosphere more effectively than gas alone. This phenomenon may also clarify why Pluto’s upper atmosphere hovers around -333 degrees F (-203 degrees C).
Related: Why is Pluto not considered a planet?
However, validating this theory has proven challenging over the years, primarily due to Charon, Pluto’s large moon. Its close orbit around the icy dwarf means their thermal signals frequently overlap in telescope measurements. “Essentially, we couldn’t determine which part of the signal belonged to Charon and which to Pluto’s haze,” Bertrand explained.
The researchers behind the 2017 study forecast that Pluto’s haze would significantly illuminate the planet at mid-infrared wavelengths. At that time, they indicated that testing this hypothesis would require future technology. That opportunity arose in 2022 when JWST’s advanced infrared instruments could finally isolate signals from both celestial bodies. As anticipated, the faint infrared signature of Pluto’s haze matched the predictions.
“In planetary science, it is rare to validate hypotheses so quickly, especially within just a few years,” remarked Xi Zhang, a planetary scientist at the University of California, Santa Cruz, who led the 2017 team, stated. “That is why we feel exceptionally fortunate and excited.”
These discoveries also suggest the potential that other hazy worlds, like Neptune’s moon Triton and Saturn’s moon Titan, possess similar haze-driven climates, Bertrand noted.
Researchers also proposed that Earth’s distant past may share some characteristics with these findings. It is conceivable that Earth was once enveloped in haze composed of organic particles prior to the oxygenation of our atmosphere. This could have helped stabilize temperatures and facilitate the emergence of life.
“Investigating the haze and chemistry of Pluto may yield new insights into the conditions that made early Earth hospitable,” Zhang concluded.
Source: www.livescience.com