Although we do know some things about the Sun - it's big and hot for example - in many ways it remains a great mystery to scientists. In a bid to shed some more light on our closest star, NASA launched its most advanced spacecraft ever designed to study the Sun in February this year. The goal of the the Solar Dynamics Observatory (SDO) is to help us understand where the Sun's energy comes from, explore its inner workings, and learn more about how energy is stored and released in the Sun's atmosphere. A nice side benefit will also be the capture of stunning images – the first of which have just been released.
During its five-year mission, the SDO will examine the Sun's magnetic field and also provide a better understanding of the role the Sun plays in Earth's atmospheric chemistry and climate. SDO will determine how the sun's magnetic field is generated, structured and converted into violent solar events such as turbulent solar wind, solar flares and coronal mass ejections. These immense clouds of material, when directed toward Earth, can cause large magnetic storms in our planet’s magnetosphere and upper atmosphere.
Since launch, engineers have been conducting testing and verification of the spacecraft’s components. Now fully operational, the SDO will provide images with clarity 10 times better than high-definition television and will return more comprehensive science data faster than any other solar observing spacecraft.
SDO will send 1.5 terabytes of data back to Earth each day, which is equivalent to a daily download of half a million songs onto an MP3 player. The observatory carries three state-of the-art instruments for conducting solar research.
The Helioseismic and Magnetic ImagerThis maps solar magnetic fields and looks beneath the Sun’s opaque surface. The experiment will decipher the physics of the Sun’s activity, taking pictures in several very narrow bands of visible light. Scientists will be able to make ultrasound images of the Sun and study active regions in a way similar to watching sand shift in a desert dune. The instrument’s principal investigator is Phil Scherrer of Stanford University. HMI was built by a collaboration of Stanford University and the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alto, Calif.
The Atmospheric Imaging AssemblyThis is a group of four telescopes designed to photograph the Sun’s surface and atmosphere. The instrument covers 10 different wavelength bands, or colors, selected to reveal key aspects of solar activity. These types of images will show details never seen before by scientists. The principal investigator is Alan Title of the Lockheed Martin Solar and Astrophysics Laboratory, which built the instrument.
The Extreme Ultraviolet Variability ExperimentThis measures fluctuations in the Sun’s radiant emissions. These emissions have a direct and powerful effect on Earth’s upper atmosphere - heating it, puffing it up, and breaking apart atoms and molecules. Researchers don’t know how fast the Sun can vary at many of these wavelengths, so they expect to make discoveries about flare events. The principal investigator is Tom Woods of the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. LASP built the instrument.
First ImagesSome of the first images from the spacecraft show never-before-seen detail of material streaming outward and away from sunspots. Others show extreme close-ups of activity on the Sun’s surface. The spacecraft also has made the first high-resolution measurements of solar flares in a broad range of extreme ultraviolet wavelengths.
"These amazing images, which show our dynamic Sun in a new level of detail, are only the beginning of SDO's contribution to our understanding of the Sun," said SDO Project Scientist Dean Pesnell of Goddard.
SDO is the first mission of NASA's Living with a Star Program, or LWS, and the crown jewel in a fleet of NASA missions that study our Sun and space environment. The goal of LWS is to develop the scientific understanding necessary to address those aspects of the connected Sun-Earth system that directly affect our lives and society.