Three years ago the very first images from the Solar Dynamics Observatory (SDO) were beamed back to earth. Since then, NASA’s SDO has effectively had continuous coverage of the Sun’s rise towards solar maximum, the period of the most intense solar activity in the 11 year solar cycle. NASA has now provided a fascinating snapshot of this ongoing research in the form of a time-lapse video that squeezes three years of solar activity into three minutes of footage.
Living With a Star
Launched aboard an Atlas V rocket on Feb. 11 2010 the SDO is the crown jewel in a fleet of NASA missions to study our sun. It is the cornerstone of Living With a Star (LWS), a NASA initiative to develop the understanding needed to address those aspects of the Sun and Solar System that directly affect our lives. The second LWS mission, the Van Allen Probes, was launched on August 30, 2012 with the aim of determining how charged particles near the Earth are accelerated to hazardous energies that affect satellites, astronaut safety, and high-altitude aircraft. Also included in the LWS mission schedule is the Balloon Array for Radiation-belt Relativistic Electron Losses (BARREL), which will measure the high-energy particle precipitation from the radiation belts into our Earth’s atmosphere, plus the Solar Probe Plus mission and Solar Orbiter Collaboration. Crucially, the SDO is studying how solar activity is created and how it, in turn, creates space weather. This activity comes in the form of changes in radiation, the solar wind, magnetic fields and other factors that constitute space weather similar to the changes in temperature, rainfall and winds that affect weather on Earth.
The SDO is observing the interior of the Sun where the magnetic field – the catalyst for space weather – is created. It is also studying the solar surface to measure the magnetic field and solar atmosphere, along with the extreme ultraviolet irradiance of the Sun that is critical to understanding the behavior of the outer layers of the Earth’s atmosphere.
The SDO study is already helping scientists to better predict solar flares and rising magnetic fields (coronal mass ejections) which can interfere with satellites in space and send radiation and solar material toward Earth.
Solar snapshot
The SDO's on-board Atmospheric Imaging Assembly (AIA) captures a shot of the Sun every 12 seconds in 10 different wavelengths sending 1.5 terabytes of data back to Earth each day.
The images shown in the video below are based on a wavelength of 171 angstroms (the extreme ultraviolet range) enabling us to see solar material at around 600,000 kelvin (about 1.08 million F). The Sun’s 25-day rotation is easily visible in this wavelength showing us how solar activity has increased over the three years.
What we are seeing is essentially a time-lapse of those three years at a pace of two images per day, two frames per image at 29.97 fps.
During the video you may notice the Sun appears to increase and decrease in size. This is because the distance between the SDO and the Sun is not always constant. The video, however, is remarkably stable despite the fact that SDO is moving around Earth at 6,876 mph and the Earth orbits the Sun at 67,062 mph.
Noteworthy events that appear briefly in the main sequence of this video include:
- 00:30:24 Partial eclipse by the moon
- 00:31:16 Roll maneuver
- 01:11:02 August 9, 2011 X6.9 Largest solar flare
- 01:28:07 Comet Lovejoy, December 15, 2011
- 01:42:29 Roll maneuver
- 01:51:07 Transit of Venus, June 5, 2012
- 02:28:13 Partial lunar eclipse
Source: NASA/SDO
