NASA's mission to see how much water Earth has is on the go. The first flights of the SnowEx are finished.

NASA has reported that scientists do not really know how much snow the Earth has. Snow is one of Earth's water resources and not much is known about it. NASA is using a really good view from space to observe all sides of Earth as an interconnected system, SnowEx. However, there are still slight difficulties they are facing.

NASA needs to know how much water is stored in snow-covered places. Water availability for drinking, agriculture and hydropower is as important as knowing the amount of snow storing water. NASA cannot measure the exact amount of the snow on Earth. They are now using SnowEx to do it.

The SnowEx is using five aircrafts for testing 10 sensors that will be used to monitor the snows from space, WJLA stated. "It would be, I would say, a monumental leap in our ability to forecast water supply if we had this kind of information," said Noah Molotch, a member of the science team for the experiment. The fresh water of approximately one-sixth of the population on Earth is from snow. It melts and flows into waterways, said Ed Kim, a NASA researcher and lead scientist for SnowEx. That mere fact is very important for people, he added.

Snow has negative implications for people too. It becomes flood, brings drought and even political permanence when water is in short supply, Kim said. The main thing that can tell how much water will melt from the snow on mountains each spring is a measurement named snow water equivalent. However, there are many different levels in different snow banks, it is hard to measure.

NASA is going to use two SnowEx sensors for snow depth. Four sensors for measuring snow density, two thermal infrared sensors to measure temperature. Lastly, a hyperspectral imager and a multispectral imager for measuring how much sunlight the snow is getting that helps to know how speedy its melting phase is.