The most extensive plans need a little luck, even in space.
In October 2022, A.J James Webb Space Telescope (JWST or Webb) viewed as CharikloIt is a small, ringed asteroid blocking a star. This event, called a cloud, is marked as Webb’s first. At the end of the month, Webb turned towards Chariklo again and scored another victory: for the first time, astronomers analyzing telescope data detected clear signs of water ice, the existence of which had only been hinted at until now. These observations will guide astronomers to a better understanding of the nature and behavior of small bodies in the outer reaches of our solar system.
But the two acts almost never happened.
Although it is the largest of its kind, Chariklo is still too small and far too small for the mighty Webb to shoot straight. Instead, astronomers decided to study them through magic, an indirect but powerful way to study small objects like Chariklo. But the team didn’t know if and when the star — without which a cloud wouldn’t happen — would fall into Webb’s field of view. This made Chariklo part of Webb Opportunity target (Opens in a new tab) Software: If the asteroid happens to pass in front of a star, the software will allow astronomers to temporarily interrupt the telescope’s schedule to observe the event.
The team calculated only a 50% chance that Webb would see a bright enough star with an interesting object like the Chariklo cross in the foreground. After its launch in 2021, when Webb underwent routine trajectory corrections to keep it firmly where it stood in space, the team continued to project and revise its list of possible occultations. Late last year, astronomers ended up on the positive side of that 50% when they discovered with “amazing good luck” that Chariklo was on its way to hide a star that had also fallen into Webb’s view.
“This was the first attempt at cloaking my stars with Webb,” the team at NASA wrote. statment (Opens in a new tab) Published Wednesday (January 25). “A lot of hard work has gone into defining and refining predictions for this unusual event.”
On October 18, 2022, Chariklo and its two ring system crossed in front of a star. Use of a near-infrared webcam (nirkam), astronomers monitored the star’s brightness for an hour. The resulting data showed a decrease in the star’s brightness as expected: when the asteroid’s rings first hid the star when the eclipse began, and again when the last of its rings concluded the disappearance.
“The shadows produced by Chariklo’s rings were clearly detected, demonstrating a new way to use Webb to explore solar system objects,” the team wrote in the statement.
Creatures like Chariklo are summoned CentaursThanks to its hybrid nature. (Centaurs are mythical horse-human hybrids.) They look like asteroids but act like comets – Complete with visible tails. Their home is unstable Orbit between Jupiter and Neptune, hosting thousands of centaurs of various shapes and sizes. As interesting as they are, their small size and vast distances make them difficult to study. The composition of even the largest centaur, Chariklo—still tiny at 160 miles (250 km) in diameter and distant at 2 billion miles (3.2 billion km) from us—is It’s not understandable. also, previous search He hinted at the existence of water ice somewhere in the Chariklo system, but had not yet definitively discovered it.
In this latest search, astronomers point to Webb in Chariklo again. This time, they used the telescope’s Near Infrared Spectrometer (NIRSpec) instrument to measure sunlight reflected by Chariklo and its rings. The resulting spectrum showed three absorption bands from water ice, marking the first clear indication of crystalline ice.
The presence of crystal ice likely indicates that Chariklo is under constant bombardment, according to Dean Haynes, an astronomer at the Space Telescope Science Institute in Maryland. “Because high-energy particles transform ice from a crystalline state to an amorphous state, the detection of crystalline ice indicates that the Chariklo system experiences continuous small collisions that either expose original material or trigger crystallization processes,” Heinz said in the NASA statement.
Astronomers are one step closer to studying the Chariklo system, but there is still much still unknown about the Centaurs. The spectrum analyzed in the latest research includes information about the system as a whole, but at present, it is difficult to differentiate the data between Chariklo and its loops.
For example, although astronomers have spotted the first obvious signs of crystalline water ice, they don’t know for sure where the ice is in the asteroid system. Pablo Santos Sanz, an astronomer at the Institute of Andalusia in Spain who was involved in this research, said in a statement.
“we hope [to] Gain insight into why this small body even has rings at all, and possibly discover new fainter rings,” said Santos-Sanz.
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