VOA慢速英语--新的火星水冰地图可以帮助确定最佳着陆点

New Map of Mars Water Ice Can Help Identify Best Landing Spots

Scientists have created a new map that aims to identify the best sources of water on Mars.

Water is considered a critical resource to support future exploration activities on Mars. Scientists believe the Red Planet contains large amounts of water. But searching from Earth for the best supplies is not easy.

The American space agency NASA has worked for years to identify the best spots for such water. Most of the water on Mars exists as ice because of extremely cold temperatures.

A new study describes and provides detailed¹ mapping for the most likely areas to contain water ice. The study appeared recently in Nature Astronomy. It is part of a project called Subsurface Water Ice Mapping, or SWIM.

NASA says the SWIM project combines 20 years of data collected by several of the agency's Mars explorers. Researchers at the Planetary Science Institute in Tucson, Arizona, are leading the research, with support from NASA's Jet Propulsion Laboratory in California.

Gareth Morgan is a scientist at the Planetary Science Institute and helped lead the research. He said in a statement, "The goal of SWIM is to provide maps of potential buried ice deposits to support the selection of human landing sites."

He added that Mars ice is a critical resource that could be used for many things, including providing drinking water for humans, growing plants for food, and producing methane² fuel and breathable air. "But the most important is to provide fuel for the return trip home to Earth," Morgan said.

Researchers have already experimented with methods that could use water ice on Mars to produce fuel, as well as oxygen.

Richard Davis leads NASA's efforts to find resources on Mars in preparation for sending humans to the Red Planet. He said the identification of water sources on Mars could also help in the search for life, which would likely be found near the water. "The next frontier for Mars is for human explorers to get below the surface and look for signs of microbial life," Davis said.

NASA says most scientists and engineers believe the most reachable subsurface ice exists below polar areas of Mars in the northern hemisphere. The new map centered on these areas -- south of the polar area but north of the equator -- because they hold more favorable conditions for humans. Spacecraft landings would also be easier there.

The map identifies two specific areas on Mars where subsurface ice could likely be found. The first sits among plains in an area known as Arcadia Planitia. Scientists believe the area was formed by ancient volcanic³ flows. The other contains glacier⁴-filled lowlands in an area called Deuteronilus Mensae.

The study identified the areas using five different methods that examined datasets from past Mars explorers. They included NASA's Mars Odyssey⁵, Mars Reconnaissance Orbiter and the Mars Global Surveyor.

The process was not designed to measure water ice directly, Gareth Morgan explained. Instead, it was meant to predict the probability of ice supplies based on observed conditions. He said things such as high levels of hydrogen and high radar-wave speeds can suggest that ice is present. Scientists can also look at the rate at which temperatures change on a surface.

NASA says it plans to use the new research to prepare for discussions with top experts to examine possible human landing areas on Mars.

NASA also recently announced it had signed an agreement with international partners to develop a future robotic Mars mapping mission to search for water-ice. The partnership⁶ includes the space agencies of Italy, Canada and Japan.

Additional mapping efforts in the 2020s "could help make human missions to Mars possible as early as the 2030s," NASA said. For now, NASA officials plan to keep searching for the best place on Mars to send astronauts so they will have enough local water-ice resources to support their activities.

Words in This Story

potential – adj. possible

deposit – n. a layer of a substance that has developed from a natural or chemical process

frontier – n. the limits of what is known or what has been done before in an area of knowledge or activity

subsurface – n. the area below Earth's surface

polar – adj. relating to the north or south pole regions

plain – n. a large area of flat land

glacier – n. a very large area of ice that moves slowly down a slope or valley or over a wide area of land

mission – n. the flight of a spacecraft to perform a certain task or job

1 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

2 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

3 volcanic   

adj.火山的；象火山的；由火山引起的

参考例句：

• There have been several volcanic eruptions this year.今年火山爆发了好几次。
• Volcanic activity has created thermal springs and boiling mud pools.火山活动产生了温泉和沸腾的泥浆池。

4 glacier   

n.冰川，冰河

参考例句：

• The glacier calved a large iceberg.冰河崩解而形成一个大冰山。
• The upper surface of glacier is riven by crevasses.冰川的上表面已裂成冰隙。

5 odyssey   

n.长途冒险旅行；一连串的冒险

参考例句：

• The march to Travnik was the final stretch of a 16-hour odyssey.去特拉夫尼克的这段路是长达16小时艰险旅行的最后一程。
• His odyssey of passion, friendship,love,and revenge was now finished.他的热情、友谊、爱情和复仇的漫长历程，到此结束了。

6 partnership   

n.合作关系，伙伴关系

参考例句：

• The company has gone into partnership with Swiss Bank Corporation.这家公司已经和瑞士银行公司建立合作关系。
• Martin has taken him into general partnership in his company.马丁已让他成为公司的普通合伙人。