Picture of the Day: The Sun – One Year, One Image
THE SUN – ONE YEAR, ONE IMAGE
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.
The image above 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.
SDO’s Atmospheric Imaging Assembly captures a shot of the sun every 12 seconds in 10 different wavelengths. The composite image shown here is 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.
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. [Source: Solar Dynamics Observatory]