Soil moisture plays a major role in how Earth’s biosphere works. Although only 0.001% of Earth’s total water resides in the first metre of dirt beneath our feet, topsoil affects how water, energy and carbon are exchanged between the Earth and the atmosphere. It also affects the absorption of carbon dioxide. SMAP will give us a more comprehensive understanding of how Earth operates as a whole, and how climate change is dependent on Earth’s land and air cycles working together.
Measurements from SMAP will also help create better weather forecasts, including the prediction of floods and the monitoring of droughts. Growing conditions for crops will be better forecasted as well, which means that SMAP will improve how humanitarian food assistance is directed to affected areas in need.
The mission is an impressive one. Every two to three days, the spacecraft will map the entire globe using the largest rotating antenna of its kind that NASA has ever deployed. And it will do so for at least three years, providing the most accurate and highest-resolution maps of soil moisture ever obtained.
SMAP is being launched on a United Launch Alliance Delta II rocket from Vandenberg Air Force Base in California, USA at 6:20am PST (that’s Friday 30 January, 1:20am AEDT). NASA’s live coverage begins approximately two hours before the launch. To watch it live, go to the NASA TV site.