If you want to know how much it rains on Earth, you must listen to the clouds.
A new satellite with a Colorado-built listening system will begin doing just that after its Thursday launch.
The Global Precipitation Measurement Core Observatory, built in partnership between NASA and the Japanese space agency JAXA, is designed to answer questions about how much rain and snow falls from the sky in places where it's not monitored, including over wildlands and oceans.
"It's able to do what previous systems have not been able to do," said Kevin Cook, with the Colorado Springs-based Space Foundation.
Measuring the water cycle has become more important in recent years as scientists have observed changing climatic patterns that have left some areas in severe drought. As climate shifts, scientists suspect, the way water moves through the atmosphere could change, too.
"The observatory's data acts as the measuring stick by which partner observations can be combined into a unified data set," NASA said in a news release. "The data will be used by scientists to study climate change, freshwater resources, floods and droughts, and hurricane formation and tracking."
Efforts have been made for years to monitor rain from space. The earliest weather satellites took pictures of clouds that forecasters used to discern rain probabilities.
The new satellite uses a mix of technologies to take out the guesswork by measuring the moisture content of clouds and determine how much rain, snow and even fine droplets of mist hit the planet.
In Broomfield, engineers at Ball Aerospace created the Global Precipitation Measurement Microwave Imager to accomplish a big part of the mission.
Clouds, explained Ball project manager Don Figgins, can be measured by the radio waves they reflect. The same method can determine temperature and examine precipitation that's falling.
"We pick up all the emissions in the microwave frequency," Figgins explained of the 10-foot-tall device that's aboard the observatory.
The device will probe the planet with a scanner that spins every two seconds. On each rotation, the scanner undergoes four checks to make sure it is pulling in the right information. Using electronic filters, the machine will tune in to the faint microwave emissions reflected by clouds, rain and snow.
All that effort is being made to measure rain because freshwater is relatively rare. While two-thirds of the planet is covered in water, only 2 percent of that is freshwater needed to sustain life.
As the climate patterns shift and the planet's population grows, water supplies are being closely watched and the satellite's global picture could be crucial.
"Understanding the water cycle will help us prepare for drought," Figgins said.
The Colorado-built instrument was shipped to Japan, where it is being mated with the satellite and its Japanese-built radar. The observatory's radar will bounce radio waves off the planet to measure rain and snow, providing 3-dimensional imagery, NASA said.
The satellite will launch aboard a Mitsubishi rocket from Japan's Tanegashima Space Center.
Cook said the venture shows the growing partnership in orbit between Japan and America.
"The collaboration with Japanese is tremendous," Cook said.
And it could also mean good things in the future for Ball Aerospace, which employs 2,700, he said.
"As we like to point out, Colorado is a major player in domestic and international aerospace," Cook said. "Its a positive thing no doubt about it."
Ball, meanwhile, is hoping the science behind the rain measurement device could see wider use.
Figgins said the Air Force is pondering the technology for future weather satellites.
watch the launch
The Space Foundation's Discovery Center at 4425 Arrowswest Drive in Colorado Springs is hosting a watch party Thursday for the launch of the Global Precipitation Measurement satellite.
Admission to the Discovery Center will be free from 10 a.m.to 1 p.m.
The center will have a live feed of the launch from Japan and visitors also can see the NASA film "Water Falls" on the center's globe-shaped Science on a Sphere screen.