Pluto’s largest moon, Charon, began as a beautiful, soft red grape until someone appeared, most peeled it, tried to soften it, then gave up and walked away, letting the poor moon seemed like the absolute parody it is. . Okay, maybe that’s not exactly what happened, but Charon just seems like a disaster and scientists want to know why. It doesn’t matter what your soft equator is, but what about your red cap? Where does it come from and why is it red?
In two recent studies published in the Science Advances and Geophysical Research Letters, scientists at the Southwest Research Institute (SwRI) combined data from NASA’s New Horizons mission with new laboratory experiments and exospheric modeling to reveal the probable composition of the red layer. of Pluto’s moon Charon and how it was made. may have formed. This first description of Charon’s dynamic methane atmosphere using new experimental data provides a fascinating insight into the origins of this moon’s red spot as described in the two recent articles.
Scientists at the Southwest Research Institute combined data from NASA’s New Horizons mission with new laboratory experiments and exospheric modeling to reveal the likely composition of the red layer of Pluto’s moon Charon and how it might have formed. New findings suggest that drastic seasonal rises in Charon’s fine atmosphere, combined with light breaking the condensed methane frost, may be key to understanding the origins of Charon’s red polar zones. (Credit: NASA / Johns Hopkins APL / SwRI)
“Before New Horizons, the best images of Pluto’s Hubble only revealed a diffuse spot of reflected light,” said Randy Gladstone of SwRI, a member of the New Horizons scientific team. “In addition to all the fascinating features discovered on Pluto’s surface, the overflight revealed an unusual feature to Charon, a striking red cap centered at its north pole.”
Remove all ads from Universe Today
Join our Patreon for just $ 3!
Enjoy the ad-free experience for a lifetime
Shortly after the 2015 meeting, New Horizons scientists proposed that a “toline-like” reddish material at Charon’s pole could be synthesized by ultraviolet light that shattered methane molecules. These are captured after escaping from Pluto and then frozen in the polar regions of the Moon during their long winter nights. Tolins are sticky organic wastes formed by light-driven chemical reactions, in this case the ultraviolet glow Lyman-alpha dispersed by interplanetary hydrogen molecules.
“Our results indicate that drastic seasonal increases in Charon’s fine atmosphere, as well as light breaking the condensed methane frost, are key to understanding the origins of Charon’s red polar zone,” said Dr. Ujjwal. Raut de SwRI, lead author of the article Science Advances. “This is one of the most illustrative and clear examples of surface-atmospheric interactions observed to date in a planetary body.”
The team realistically replicated Charon’s surface conditions at SwRI’s new Center for Astrophysics and Space Science Experiments (CLASS) to measure the composition and color of hydrocarbons produced in the winter hemisphere. Charon when methane freezes under the Lyman-alpha glow. The team introduced the measurements into a new atmospheric Charon model to show that methane decomposes into waste at the north polar point of Charon.
“Our team’s new‘ dynamic photolysis ’experiments provided new limits to the contribution of interplanetary Lyman-alpha to the synthesis of Charon’s red material,” Raut said. “Our experiment condensed methane in an ultra-high vacuum chamber under exposure to Lyman-alpha photons to faithfully replicate the conditions at Charon’s poles.”
SwRI scientists also developed a new computer simulation to model Charon’s thin methane atmosphere.
“The model points to ‘explosive’ seasonal pulses in Charon’s atmosphere due to extreme changes in conditions during Pluto’s long journey around the Sun,” said Dr. Ben Teolis, lead author of Geophysical Research Letters .
The team introduced the results of SwRI’s ultra-realistic experiments into the atmospheric model to estimate the distribution of complex hydrocarbons arising from the decomposition of methane under the influence of ultraviolet light. The model has polar zones generating mainly ethane, a colorless material that does not contribute to a reddish color.
“We believe that ionizing radiation from the solar wind breaks down polar ice cooked with Lyman-alpha to synthesize increasingly complex, red materials responsible for the unique albedo on this enigmatic moon,” Raut said. “Ethane is less volatile than methane and stays frozen on the surface of Charon long after the spring sun rises. Exposure to solar wind can turn ethane into persistent reddish surface deposits that contribute to the layer. Charon’s Red. “
“The team is ready to investigate the role of the solar wind in the formation of the red pole,” said Dr. Josh Kammer of SwRI, who secured continued support from NASA’s New Frontier data analysis program.
Charon in depth
As mentioned, Charon is the largest of the five moons of Pluto and the largest known satellite in relation to its parent body. It was discovered in June 1978 by James Christy and Robert Harrington at the United States Naval Observatory in Flagstaff, Arizona. Charon’s surface is cold and covered with methane and nitrogen ice, and possibly water ice as well. Ground observations at the Gemini Observatory in Hawaii have suggested that Charon may even show cryovolcanism in the form of ice particles. Although the Hubble Space Telescope photographed both Pluto and Charon in 1994, it wasn’t until the New Horizons spacecraft flew through the Pluto system in 2015 that Charon obtained its first (and only) foreground study. . The pioneering spacecraft revealed a world with a geologically chaotic history, with the great system of canyons along the equator of the Moon possibly indicating a titanic geological upheaval at some point in Charon’s past.
Charon’s high-resolution images were taken by the Long Range Reconnaissance Imager on NASA’s New Horizons spacecraft shortly before the nearest approach on July 14, 2015, and overlaid with an enhanced color of the Ralph Multispectral Visual Imaging Camera (MVIC). The highland craters of Charon at the top are broken by a series of canyons, and replaced at the bottom by the undulating plains of the informally named Vulcan Planum. The scene covers Charon’s width of 1,214 kilometers (754 miles) and resolves details as small as 0.8 kilometers (0.5 miles). (Credit: NASA / JHUAPL / SwRI)
When will we return to Pluto’s system, and what other secrets will we reveal about Pluto’s largest satellite? Only time will tell, and that’s why we’re science!
As always, keep doing science and keep looking!
Press Release: Southwest Research Institute
Sources: Science Advances, Geophysical Research Letters, NASA Solar System Exploration, Space Facts, NASA
Like this:
I like loading …