VOA慢速英語: 美國航空航天局關(guān)注地球健康

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US Space Agency Keeping Watch on Earth’s Health

The past year has been the busiest 12-month period for the American space agency in more than 10 years.

The National Aeronautics and Space Administration, NASA, launched three missions in 2014. It began a fourth project earlier this month. A fifth launch is set for this Thursday, January 29.

But the instruments sent into Earth's orbit are not searching the skies for distant stars or planets. They are instead examining how the Earth is reacting to rising temperatures -- something known as global warming or climate change.

After the launch this week, NASA will have 18 instruments in Earth's orbit examining our planet.

Last February, NASA launched GPM, or the Global Precipitation Measurement mission. NASA's Tom Wagner is an Earth scientist.

"What that's going to do is improve our understanding of precipitation. It'll be able to measure how much snow is in the atmosphere. And that'll overall improve our understanding of rainfall."

GPM was followed by the Orbiting Carbon Observatory project, also known as OCO-2. Tom Wagner says this mission is important because carbon dioxide, or CO-2, emissions are a main reason the planet is warming.

"One of the most important things with carbon dioxide is we need to know where it's coming from, but we need to know where it goes. Does it get taken up by the ocean, for example. Is it being released by (the) thawing of the Arctic? And, if we wanna figure out where the planet's gonna be, say in 50 or 100 years, those are the kinds of processes we need to understand."

Also last year, two instruments were placed on the International Space Station.

"It's the first time we're putting instruments on the Space Station to look down at Earth. The space station represents this incredible platform because it has things like a lot of power."

One instrument is called RapidScat. It measures how fast winds are moving on the surface of the ocean. Scientists can use that information to improve their knowledge of the climate and make better weather predictions. The second instrument is known as the Cloud-Aerosol Transport System or CATS. Mr. Wagner says it will use lasers to learn about the links between pollution and cloud formation.

This week, NASA plans to launch SMAP -- or Soil Moisture Active Passive. It will examine the water cycle, which is important to life on Earth. Mr. Wagner says SMAP will work with other instruments to study the health of our planet.

"And, the simple fact is this: The Earth is all interconnected. And, if you wanna understand it, you need to make measurements all over the place, all the time, so you can get a total picture of what's going on. And satellite is one of the best ways to do that."

He says the stored information from satellites can help weather experts make better predictions. He says it can also help farmers and ocean and land managers make better decisions as they react to global warming.

I'm Christopher Cruise.

This report was based on a story by VOA Science Correspondent Rosanne Skirble. Christopher Cruise wrote this story for VOA Learning English. George Grow was the editor.

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Words in This Story

precipitation – n. water that falls to the ground as rain or snow

carbon dioxide – n. a gas that is produced when people and animals breathe out or when certain fuels are burned and that is used by plants for energy

emissions – n. something sent out or given off; the act of producing or sending out something (such as energy or gas) from a source

taken up by – idiomatic absorbed; to take in (something, such as a liquid) in a natural or gradual way

thaw(ing) – v. to become warm enough that snow and ice melt

platform – n. a place on which an instrument or tool can be mounted or placed

interconnected – adj. having the quality of being connected with something else

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