US space agency Nasa is gearing up to launch its $964-million Plankton, Aerosol, Cloud, Ocean Ecosystem (PACE) satellite from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida on 7 February. The spacecraft, which will provide valuable insights about Earth’s health, is set to launch aboard SpaceX’s Falcon 9 rocket.
After its launch, the PACE satellite, which is equipped with advanced polarimeters—instruments that measure light properties— will scan the Earth and collect data on the chemical composition, movement, and interaction of aerosols and clouds, a press statement on Nasa’s website revealed.
"Polarization is something that we don’t have an intuitive sense for because our eyes don’t see it,” Kirk Knobelspiesse, polarimetry lead for the PACE mission said on the website. “If you saw the world through eyes that could see polarization, like our sensors can, you would see rainbows everywhere.”
When light interacts with a cloud or an aerosol particle, it can swing more in one direction than the others, making it polarized light. This characteristic of light can help scientists better understand interactions of aerosols and water droplets in the sky, Nasa explained. Polarimeters measure the angle at which the light is polarized, which can reveal characteristics of the particles in the atmosphere.
Although scientists have been observing aerosols from space for decades, they haven’t had access to polarimetry data for a decade, Otto Hasekamp, a senior scientist said in the Nasa statement.
PACE will scan Earth every two days, collecting massive amounts of data on the characteristics and interactions of aerosols and clouds. Nasa scientists explained in the statement that they want to measure the properties of aerosols because “aerosols affect climate.”
Data from the polarimeters will also provide real-time insights about air pollution. PACE will enable scientists to identify aerosols and also better understand how they affect air quality.
In the mission statement, Nasa officials wrote that PACE will use its three science instruments, the two polarimeters as well as the Ocean Color Instrument "to collect data on clouds, aerosols and phytoplankton growth that can determine ocean color.”
Examining the colour and amount of light will provide scientists with more information on the types and locations of microscopic algae, which are crucial to the health of Earth’s oceans and its marine life, the officials added.