Study: Saturn's Moon Titan Has Huge Layer of Methane-filled Ice
2024-11-11
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1New research suggests Saturn's moon Titan has a thick ice cover that could be warming lower areas and supporting molecular growth.
2Scientists at the University of Hawaii carried out the new study.
3It appears in The Planetary Science Journal.
4The findings add to existing evidence that Titan may hold the right mix of materials to support possible life.
5No life forms have been confirmed on Titan, a cold, icy world.
6But past studies suggest the moon now has a large layer of ice that once supported widely flowing water on the surface.
7Titan is also thought to contain a dense atmosphere rich in nitrogen and methane, both of which are found in Earth's own atmosphere.
8NASA reports Saturn has a total of 146 moons orbiting it, more than any other planet.
9Titan, an ice giant, is the largest of them.
10For more than 10 years, NASA's Cassini spacecraft studied Saturn "and its complex system of rings and moons," the space agency said.
11The new study used NASA data to closely examine surface details of Titan.
12The researchers used computer modeling to examine different elements of Titan's surface.
13One of the main discoveries was that many craters examined on Titan's surface were not as deep as some other moons.
14The team reported that in some cases, craters were hundreds of meters shallower, or less deep, than scientists expected.
15In addition, only 90 craters were identified on the whole moon.
16"This was very surprising because, based on other moons, we expect to see many more impact craters on the surface," said University of Hawaii's Lauren Schurmeier, who led the study.
17She said the research team had also expected to see much deeper craters.
18"We realized something unique to Titan must be making them become shallower and disappear relatively quickly," she said.
19Computer modeling carried out by the researchers showed how the surface might have changed to remove signs of major impact craters.
20The researchers said one of the most likely causes of such change was that the moon's icy surface is covered with a thick layer of solid water ice, with methane gas trapped inside.
21The team said the data examinations suggest Titan has a methane-filled icy crust that is from five to 10 kilometers thick.
22The modeling operations run by the scientists produced images that looked similar to crater formations on Titan's surface.
23Schurmeier said the methane crust, "warms Titan's interior" and can cause surprisingly fast changes to the surface structure.
24Schurmeier noted, for example, that crater shallowing on Titan is believed to be happening at a rate "that is close to that of fast-moving warm glaciers on Earth."
25The surface of Titan is estimated to be about minus 179 degrees Celsius.
26Because of this extreme cold, liquids on the moon's surface take the form of ice, with methane gas locked inside, the researchers said.
27This gas could help warm surface levels beneath, possibly permitting molecules to rise toward the surface.
28Schurmeier said studying the thickness of Titan's icy crust is important because it might help explain how the moon's atmosphere began to develop.
29The measurements could also provide additional information on Titan's changing climate.
30"Titan is a natural laboratory to study how the greenhouse gas methane warms and cycles through the atmosphere," she said.
31The resulting information, she added, can provide important insights about such processes happening on Earth.
32NASA's Cassini spacecraft ended it mission in 2017, when it crashed into Saturn's atmosphere.
33But the U.S. space agency has plans to send another explorer to Titan in 2028.
34That mission calls for a spacecraft called Dragonfly to travel to Titan to observe many different areas.
35The planned explorer, called a rotorcraft, operates similar to a helicopter.
36I'm Bryan Lynn.
1New research suggests Saturn's moon Titan has a thick ice cover that could be warming lower areas and supporting molecular growth. 2Scientists at the University of Hawaii carried out the new study. It appears in The Planetary Science Journal. The findings add to existing evidence that Titan may hold the right mix of materials to support possible life. 3No life forms have been confirmed on Titan, a cold, icy world. But past studies suggest the moon now has a large layer of ice that once supported widely flowing water on the surface. Titan is also thought to contain a dense atmosphere rich in nitrogen and methane, both of which are found in Earth's own atmosphere. 4NASA reports Saturn has a total of 146 moons orbiting it, more than any other planet. Titan, an ice giant, is the largest of them. 5For more than 10 years, NASA's Cassini spacecraft studied Saturn "and its complex system of rings and moons," the space agency said. The new study used NASA data to closely examine surface details of Titan. 6The researchers used computer modeling to examine different elements of Titan's surface. One of the main discoveries was that many craters examined on Titan's surface were not as deep as some other moons. The team reported that in some cases, craters were hundreds of meters shallower, or less deep, than scientists expected. In addition, only 90 craters were identified on the whole moon. 7"This was very surprising because, based on other moons, we expect to see many more impact craters on the surface," said University of Hawaii's Lauren Schurmeier, who led the study. 8She said the research team had also expected to see much deeper craters. "We realized something unique to Titan must be making them become shallower and disappear relatively quickly," she said. 9Computer modeling carried out by the researchers showed how the surface might have changed to remove signs of major impact craters. The researchers said one of the most likely causes of such change was that the moon's icy surface is covered with a thick layer of solid water ice, with methane gas trapped inside. 10The team said the data examinations suggest Titan has a methane-filled icy crust that is from five to 10 kilometers thick. The modeling operations run by the scientists produced images that looked similar to crater formations on Titan's surface. 11Schurmeier said the methane crust, "warms Titan's interior" and can cause surprisingly fast changes to the surface structure. Schurmeier noted, for example, that crater shallowing on Titan is believed to be happening at a rate "that is close to that of fast-moving warm glaciers on Earth." 12The surface of Titan is estimated to be about minus 179 degrees Celsius. Because of this extreme cold, liquids on the moon's surface take the form of ice, with methane gas locked inside, the researchers said. This gas could help warm surface levels beneath, possibly permitting molecules to rise toward the surface. 13Schurmeier said studying the thickness of Titan's icy crust is important because it might help explain how the moon's atmosphere began to develop. The measurements could also provide additional information on Titan's changing climate. 14"Titan is a natural laboratory to study how the greenhouse gas methane warms and cycles through the atmosphere," she said. The resulting information, she added, can provide important insights about such processes happening on Earth. 15NASA's Cassini spacecraft ended it mission in 2017, when it crashed into Saturn's atmosphere. But the U.S. space agency has plans to send another explorer to Titan in 2028. That mission calls for a spacecraft called Dragonfly to travel to Titan to observe many different areas. The planned explorer, called a rotorcraft, operates similar to a helicopter. 16I'm Bryan Lynn. 17Bryan Lynn wrote this story for VOA Learning English, based on reports from the University of Hawaii at Manoa, the University of Lisbon and NASA. 18_________________________________________ 19Words in This Story 20layer - n. an amount of something covering a surface 21crater - n. a hole left in the ground by an object that hits it with a huge force 22impact - n. the force or action of one object hitting another 23unique - adj. different from everyone and everything else 24crust - n. a hard, dry layer of the surface of something 25glacier - n. a large mass of ice that moves very slowly, usually down a hill or valley