From people and pets to pens and pencils,
everything gives off energy in the form of heat. We’ve got special instruments
that measure thermal wavelengths, so we can tell whether something is hot, cold
or in between. Hotter things emit more thermal energy; colder ones emit less.
We have special instruments in
space, zipping around Earth and measuring the hottest and coldest places on our
planet.
We can also measure much subtler changes in
heat – like when plants cool down as they take up water from the soil and
‘sweat’ it out into the air, in a process called evapotranspiration.
This lets us identify healthy,
growing crops around the world.
The instrument that can do all this
is called the Thermal Infrared Sensor 2 (TIRS-2). It just passed a series of
rigorous tests at our Goddard Space Flight Center in Greenbelt, Md., proving
it’s ready to survive in space.
TIRS-2 is bound for the Landsat 9
satellite, which will continue decades of work studying our planet from space.
