Study: Rough Areas on Moon May Permit Water Ice to Widely Form
2021-08-09
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1A new study suggests that rough areas on the moon's surface block sunlight and permit water ice to form across wide areas.
2The U.S. space agency NASA already confirmed last year that results from two studies suggested water ice likely existed across much of the moon's surface, even during daytime.
3One of those studies centered on so-called "cold traps" observed on the moon that hold frozen water.
4These areas exist in a state of permanent darkness because temperatures are below about minus 160 degrees Celsius.
5Until now, scientists have not been sure what was permitting these traps to exist.
6Especially since the moon does not have a thick atmosphere to help water survive.
7One theory was that water molecules could be trapped on the lunar surface inside rock or other material that resulted from meteorite strikes.
8But a new study by NASA researchers provides another possible explanation for how water ice could remain in many areas of the moon's surface.
9It presents evidence that the rough, rocky surface creates shadows that permit water ice to survive.
10The researchers note that past observations suggested there were movements of water through the lunar day.
11A lunar day is the time it takes for one point on the Earth to make one complete rotation and end up at the same point in relation to the moon.
12Studies have provided evidence that the amount of water decreased on the moon's surface when sunlight was brightest and increased with less sunlight.
13The latest study was led by Björn Davidsson, a scientist at NASA's Jet Propulsion Laboratory (JPL) in California.
14He teamed up with another JPL researcher, Sona Hosseini, to carry out the research.
15The team revised past computer modeling to include rough surface areas of the moon that can be seen in images collected from NASA's Apollo missions from 1969 to 1972.
16The research results recently appeared in the publication Monthly Notices of the Royal Astronomical Society.
17The study suggests that as surface frost that forms in cold areas receives sunlight, it can then be "cycled into the moon's exosphere."
18The exosphere is the thin, outer area that forms around a planet or satellite object, such as the moon.
19"Frost is far more mobile than trapped water," Davidsson said in a statement.
20"Therefore, this model provides a new mechanism that explains how water moves between the lunar surface and the thin lunar atmosphere."
21The researchers say their study is the first to examine how shadows on the lunar surface can affect the ability of water molecules to survive as frost during the daytime.
22They noted that such research is important to help scientists better understand how water enters and leaves the moon's exosphere.
23Hosseini said understanding water as a resource is "essential" for future NASA missions or any possible private space exploration.
24She added if water ice is available in sunlit areas of the moon, future explorers could use it for fuel and drinking water.
25"But first, we need to figure out how the exosphere and surface interact and what role that plays in the cycle," Hosseini said.
26The researchers say they plan to test their theory by leading a team to develop small sensors to measure signals given off by a molecule contained in water ice.
27The sensing device will be designed to be used on small landers or robotic explorers that could be sent to the moon in future missions.
28I'm Bryan Lynn.
1A new study suggests that rough areas on the moon's surface block sunlight and permit water ice to form across wide areas. 2The U.S. space agency NASA already confirmed last year that results from two studies suggested water ice likely existed across much of the moon's surface, even during daytime. 3One of those studies centered on so-called "cold traps" observed on the moon that hold frozen water. These areas exist in a state of permanent darkness because temperatures are below about minus 160 degrees Celsius. 4Until now, scientists have not been sure what was permitting these traps to exist. Especially since the moon does not have a thick atmosphere to help water survive. One theory was that water molecules could be trapped on the lunar surface inside rock or other material that resulted from meteorite strikes. 5But a new study by NASA researchers provides another possible explanation for how water ice could remain in many areas of the moon's surface. It presents evidence that the rough, rocky surface creates shadows that permit water ice to survive. 6The researchers note that past observations suggested there were movements of water through the lunar day. A lunar day is the time it takes for one point on the Earth to make one complete rotation and end up at the same point in relation to the moon. 7Studies have provided evidence that the amount of water decreased on the moon's surface when sunlight was brightest and increased with less sunlight. 8The latest study was led by Björn Davidsson, a scientist at NASA's Jet Propulsion Laboratory (JPL) in California. He teamed up with another JPL researcher, Sona Hosseini, to carry out the research. 9The team revised past computer modeling to include rough surface areas of the moon that can be seen in images collected from NASA's Apollo missions from 1969 to 1972. The research results recently appeared in the publication Monthly Notices of the Royal Astronomical Society. 10The study suggests that as surface frost that forms in cold areas receives sunlight, it can then be "cycled into the moon's exosphere." The exosphere is the thin, outer area that forms around a planet or satellite object, such as the moon. 11"Frost is far more mobile than trapped water," Davidsson said in a statement. "Therefore, this model provides a new mechanism that explains how water moves between the lunar surface and the thin lunar atmosphere." 12The researchers say their study is the first to examine how shadows on the lunar surface can affect the ability of water molecules to survive as frost during the daytime. 13They noted that such research is important to help scientists better understand how water enters and leaves the moon's exosphere. 14Hosseini said understanding water as a resource is "essential" for future NASA missions or any possible private space exploration. She added if water ice is available in sunlit areas of the moon, future explorers could use it for fuel and drinking water. 15"But first, we need to figure out how the exosphere and surface interact and what role that plays in the cycle," Hosseini said. 16The researchers say they plan to test their theory by leading a team to develop small sensors to measure signals given off by a molecule contained in water ice. The sensing device will be designed to be used on small landers or robotic explorers that could be sent to the moon in future missions. 17I'm Bryan Lynn. 18Bryan Lynn wrote this report for VOA Learning English, based on reports from NASA and Monthly Notices of the Royal Astronomical Society. Hai Do was the editor. 19We want to hear from you. Write to us in the Comments section, and visit our Facebook page. 20___________________________________________________ 21Words in This Story 22shadow - n. a dark shape that appears on a surface when someone or something moves between the surface and a source of light 23revise - v. change something that has already been worked on 24mission - n. a flight by an aircraft or spacecraft to perform a specific task 25frost - n. a thin layer of ice that forms on surfaces, especially at night when it is cold 26mobile - adj. able to move or be moved easily 27mechanism - n. a part of a piece of equipment that does a particular job 28essential - adj. very important and necessary 29figure out - v. to understand or find something, such as a reason or a solution by thinking