In the three years since it first provided images of the sun in the
spring of 2010, NASA’s Solar Dynamics Observatory has had virtually
unbroken coverage of the sun's rise toward solar maximum, the peak of
solar activity in its regular 11-year cycle. This video shows those
three years of the sun at a pace of two images per day.
Credit: NASA's Goddard Space Flight Center
SDO’s Atmospheric Imaging Assembly captures a shot of the sun every 12
seconds in 10 different wavelengths. The images shown here are based on a
wavelength of 171 angstroms, which is in the extreme ultraviolet range
and shows solar material at around 600,000 kelvins (about 1.08 million
F). In this wavelength it is easy to see the sun’s 25-day rotation as
well as how solar activity has increased over three years.
During the course of the video, the sun subtly increases and decreases
in apparent size. This is because the distance between the SDO
spacecraft and the sun varies over time. The image is, however,
remarkably consistent and stable despite the fact that SDO orbits Earth
at 6,876 mph and Earth orbits the sun at 67,062 mph.
This image is a composite of 25 separate images spanning the period of
April 16, 2012, to April 15, 2013. It uses the SDO AIA wavelength of 171
angstroms and reveals the zones on the sun where active regions are
most common during this part of the solar cycle. Credit: NASA/SDO/AIA/S. Wiessinger. › Larger image
Such stability is crucial for scientists, who use SDO to learn more
about our closest star. These images have regularly caught solar flares
and coronal mass ejections in the act, types of space weather that can
send radiation and solar material toward Earth and interfere with
satellites in space. SDO’s glimpses into the violent dance on the sun
help scientists understand what causes these giant explosions -- with
the hopes of some day improving our ability to predict this space
weather.
NASA's Goddard Space Flight Center, Greenbelt, Md.
