Seeing Water from Space: How NASA Satellites Help Us Understand and Manage Water in a Changing World

Water is one of the most essential and misunderstood resources on Earth. We drink it, grow food with it, generate power from it, and build communities around it. But in many parts of the world—including right here in the United States—water is becoming harder to manage due to drought, population growth, and climate change.

Luckily, we’re not flying blind. NASA has developed powerful satellite tools that help us see and understand how water moves across the landscape. These tools don’t just watch rivers or clouds—they can tell us how wet the soil is, how much groundwater lies beneath our feet, and how fast water is leaving plants and soil through a process called evapotranspiration.

This post explains how three of NASA’s Earth observation missions—SMAP, GRACE-FO, and Landsat 8/9—help communities, farmers, utilities, and governments make smarter water decisions.

 
1. SMAP – Mapping Soil Moisture from Space

SMAP (Soil Moisture Active Passive) is a space-based moisture meter that scans the Earth every few days to measure how wet or dry the top layer of soil is.

Why It Matters:

• Farmers can plan irrigation more efficiently.
• Emergency managers get better wildfire and flood risk data. (Shout out to our hardworking Wildfire responder buddy Larry in La Grande, OR!)
• Meteorologists improve weather predictions. (What's harder to predict than weather?)

2. GRACE-FO – Detecting Hidden Water Changes

GRACE-FO measures changes in Earth's gravity field to estimate underground water, snow, and surface water.

Why It Matters:

• Water managers across industries can track groundwater loss.
• Policymakers (local & state especially) use it for sustainable water policy.
• Scientists or interested parties measure long-term water trends.
   

  3. Landsat 8 & 9 – Measuring Evapotranspiration and Vegetation Health

  Landsat satellites track how much water is leaving the landscape through evapotranspiration.

Why It Matters:

• Farmers monitor crop water needs.
• Water agencies understand usage patterns.
• Conservationists identify stressed vegetation.
   

  What This Means for You!

  Whether you're a student, farmer, planner, human or simply water-curious, NASA Earth observations:
  • Helps homeowners conserve water
  • Support smarter farm decisions
  • Improve local drought management
  • Influence national and global policy

Aetervaja is planning on working to bring these tools into hands-on use with modular water reuse systems and smart dashboards for agriculture. NASA satellites are helping all of us make better water decisions. Thank you NASA Scientists, Researchers, Leaders and Funding that makes this all possible!

 
References (ALA Format)

• National Snow and Ice Data Center. “Soil Moisture Active Passive (SMAP)           Data.” NSIDC.org. https://nsidc.org/data/smap
• NASA Jet Propulsion Laboratory. “Water Storage.” GRACE-FO.                                     https://gracefo.jpl.nasa.gov/science/water-storage
• Senay, G. B., et al. “Evaluating Landsat 8 evapotranspiration for water use           in the Colorado River Basin.” Remote Sensing of Environment, 2016.
• Kim, Y., et al. “Global estimates of daily evapotranspiration using SMAP                 surface and root-zone soil moisture.” Science of the Total Environment,             2023.
• Drought.gov. “Groundwater and Soil Moisture Conditions from GRACE                 Data Assimilation.” https://www.drought.gov/data-maps                                               tools/groundwater-and-soil-moisture-conditions-grace-data-                                 assimilation
• NASA Science. “Landsat Missions.” https://landsat.gsfc.nasa.gov/