Spectacular “first light” images and data from three state-of-the art instruments on NASA’s Solar Dynamics Observatory (SDO) were unveiled this week. The SDO spacecraft was launched aboard a United Launch Alliance Atlas V rocket from the Cape Canaveral Air Force Station on February 11, 2010. Image courtesy of Lockheed Martin. Two of the SDO instruments were built at the Solar and Astrophysics Laboratory of the Lockheed Martin Advanced Technology Center (ATC) in Palo Alto. The Atmospheric Imaging Assembly (AIA), a suite of four telescopes, provides an unprecedented view of the solar corona, taking images that span at least 1.3 solar diameters in multiple wavelengths nearly simultaneously, at a resolution of 0.6 arcsec and at a cadence of 10 sec or better. The Helioseismic and Magnetic Imager (HMI), designed in collaboration with Philip Scherrer and other scientists at Stanford University, studies the origin of solar variability and attempts to characterize and understand the sun’s interior and magnetic activity. The third SDO instrument, the Extreme Ultraviolet Variability Experiment (EVE), measures fluctuations in the sun’s ultraviolet output. EVE was built by the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. “We could not be more pleased with what we’re seeing from AIA. The 4096- × 4096-pixel charge-coupled device on this instrument gives us images that would require 12 high-definition televisions to display them at their native resolution,” said Alan Title of the ATC, a physicist who is principal investigator of the AIA. “AIA is now providing the kind of data we need to unravel mysteries of the sun that have been just beyond our grasp. Looking at a razor-sharp full sun in a broad range of temperature bands every 10 s will give us unprecedented insight into the processes that determine the evolution of the corona.” The AIA produces data required for quantitative studies of the evolving coronal magnetic field, and the plasma it holds, both in quiescent phases and during flares and eruptions. The primary goal of the AIA science investigation is to use these data, together with data from other SDO instruments and from other observatories, to significantly improve our understanding of the physics behind the activity displayed by the sun’s atmosphere, which drives space weather in the heliosphere and in planetary environments. Ultimately, it is hoped that the greater understanding gained of the observed processes will guide development of advanced forecasting tools needed by the user community. “HMI combined with our partner instruments on SDO – the AIA and the EVE – are providing us with the data needed to first learn if predictions of solar activity are possible,” Scherrer said. “Then, if we and our colleagues in the solar physics community are clever enough, we’ll actually develop forecast methods. This is an exciting time for studying the sun and its impact on the Earth.” The primary goal of the HMI investigation is to study the origin of solar variability and to characterize and understand the sun’s interior and magnetic activity. Because of the turbulence in the convection zone near the surface, the sun is figuratively ringing like a bell. By studying these oscillations of the visible surface of the sun, considerable insight can be gained into the processes inside. In effect, the solar turbulence is analogous to earthquakes. In a manner similar to how seismologists can learn about the interior of the Earth by studying the waves generated in an earthquake, HMI’s helioseismologists learn about the structure, temperature and flows in the solar interior. “HMI is providing us with sonograms of the sun that will show us sunspots and magnetic fields before they appear on the visible surface,” Title added. “We’re even able to see through the sun and be aware of the birth of spots on the side facing away from us, allowing us to be ready for them as they rotate into our view. Moreover, HMI’s high spatial resolution and full-sun coverage gives us much more time to study magnetic field evolution in detail.” HMI produces data necessary to determine the interior sources and mechanisms of solar variability and how the physical processes inside the sun are related to surface magnetic field and activity. Because HMI can measure the strength and direction of the magnetic field on the surface, more precise estimates of the coronal magnetic field are possible. In addition, HMI observations will clarify the relationships between internal solar dynamics and magnetic activity, providing a better understanding of solar variability and its effects. The knowledge gained will enable a major advance in the development of a reliable predictive capability for solar flares and coronal mass ejections. Solar scientists will use SDO’s third instrument, EVE, to measure the sun’s brightness in the most variable and unpredictable part of the solar spectrum. The extreme ultraviolet, or EUV, spans wavelengths from 0.1 to 105 nm. EVE collects spectra over a broad EUV to UV range from the entire sun. EVE and AIA will be able together to establish how local events like flares affect the entire solar spectrum. The goal of SDO is to understand – striving towards a predictive capability – the solar variations that influence life on Earth and humanity’s technological systems. The mission seeks to determine how the sun’s magnetic field is generated and structured, and how this stored magnetic energy is converted and released into the heliosphere and geospace in the form of solar wind, energetic particles, and variations in the solar irradiance. Flying in a geosynchronous orbit, SDO observes the sun 24 hours a day without interruption, and downlinks its data to the Science Operations Center at Stanford University. Quick-look data is available in near real time for assessment of current solar weather. Processed data will be available to both scientists and the general public as soon as its quality can be evaluated – usually about a day. Public tools for searching the SDO database and for creating a variety of movies will be available. SDO is the first mission and crown jewel in a fleet of NASA missions to study our sun. The mission is the cornerstone of a NASA science program called Living With a Star (LWS). The goal of the LWS program is to develop the scientific understanding necessary to address those aspects of the sun and solar system that directly affect life and society. The SDO will study how solar activity is created and how space weather results from that activity. Measurements of the sun’s interior, its magnetic field, the hot plasma of the solar corona and its irradiance will help meet the objectives of the SDO mission. SDO is managed by NASA’s Goddard Space Flight Center for the agency’s Science Mission Directorate at NASA headquarters in Washington, D.C. The Solar and Astrophysics Laboratory at the ATC has a 47-year-long heritage of spaceborne solar instruments including the soft x-ray telescope on the Japanese Yohkoh satellite, the Michelson Doppler imager on the ESA/NASA Solar and Heliospheric Observatory, the solar telescope on NASA’s Transition Region and Coronal Explorer, the solar x-ray imager on the GOES-N, -O and -P environmental satellites, the focal plane package on Hinode and an extreme ultraviolet imager on each of the two spacecraft in NASA’s Solar Terrestrial Relations Observatory. The laboratory also conducts basic research into understanding and predicting space weather and the behavior of the sun including its impacts on Earth and climate. The ATC is the research and development organization of Lockheed Martin Space Systems Co., a major operating unit of Lockheed Martin Corp. of Bethesda, Md. For more information, visit: www.lockheedmartin.com