The third and final instrument for NASA's Solar Dynamics Observatory (SDO) has joined the other two at NASA's Goddard Space Flight Center in Greenbelt, Md.The Atmospheric Imaging Assembly (AIA) was delivered to Goddard in preparation for SDO's scheduled launch in December 2008. The AIA was designed and built at the Solar and Astrophysics Laboratory of the Lockheed Martin Advanced Technology Center (ATC), Palo Alto, Calif.
The AIA is a suite of four telescopes designed to provide an unprecedented view of the sun’s lower corona, a part of the sun’s atmosphere relatively close to the surface. AIA’s telescopes will take nearly simultaneous images in multiple wavelengths that span an area at least 50% larger than the sun. AIA will be able to quickly create new multiple-wavelength images, about one every ten seconds, allowing scientists to create detailed movies of rapidly evolving solar storms. The multiple-wavelength view allows the imaging of gases at different temperatures, from 10,000 to 30,000,000 degrees Kelvin (~20,000 to 50,000,000 degrees Farenheit). Observing coronal gas heated to different temperatures will help scientists trace how the sun’s magnetic energy, which powers violent solar weather, is released in the corona.
"This is a very significant step for the solar physics community. Having AIA complete and undergoing integration on to the SDO spacecraft means we’re getting very close to the time when this instrument will be providing the kind of data we need to unravel mysteries of the sun that have been just beyond our grasp," said Alan Title, AIA principal investigator and a solar physicist of the ATC.
The AIA will provide new details about how the plasma and magnetic field in the corona changes during stormy activity like flares and eruptions as well as during relatively quiet times. These details are required for scientists using computer-generated models to test their theories about how magnetic energy is released in solar storms. Scientists hope observations with AIA will give them new insight into the physics behind the magnetic activity in the sun's atmosphere that drives space weather. New details about the physics show scientists how to revise their models. Comparing those revised models to AIA’s observations shows the scientists how well they simulate what was actually seen on the sun. Ultimately, scientists will use the new data from the AIA, the other instruments on SDO, and other solar observatories to improve forecasts of severe space weather. This is the goal of NASA's Living With a Star program.
The Solar Dynamics Observatory instruments, which include the AIA, the Heliospheric and Magnetic Imager and the Extreme Ultraviolet Variability Experiment, are designed to work together. Their coordinated observations will determine how the sun’s magnetic field is generated and structured, how this stored magnetic energy is converted into heat and light, how it is released as solar wind and energetic particles, and how these processes change the solar irradiance. Solar irradiance is the source of virtually all the energy that enables life on Earth.
SDO is a major component of a fleet of focused science missions developed by the NASA Heliophysics Division. Each mission will cooperate with the others as components of a Great Observatory whose goal is to understand our heliosphere – the domain of the sun.
