The sun is the star responsible for life on Earth. Without it, we would not be here and it is a constant element in our daily life. With all that in mind, it’s a real shame you shouldn’t be looking at it directly. The sun is an incredible thing and astronomers have found ways to observe it without burning its retinas. One such tool is the Solar Dynamics Observatory, an “unblinking eye” that constantly observes the sun.
SDO images are produced by capturing only a specific ultraviolet wavelength that allows scientists to see the star’s corona, which is its outermost shell. For a decade, SDO has been looking at the sun and recording every point of activity it can detect. Now, we can enjoy it all by ourselves.
The timelapse video just released by NASA is absolutely amazing. Reduce ten years of solar observations in just over an hour. Yes, it’s an hour long video, so grab a cup of coffee and enjoy it.
The video, which is available in up to 4k resolution, is impressive. It shows great activity on the star’s surface from the beginning, increasing until there are plasma magnetic loops that cover a large percentage of its surface. Then, as fast as they appear, the activity hotspots seem to fade away, leaving the star much calmer.
This is the regular cycle of the sun, where it goes from a period of high activity called the Solar Maximum to a period of low activity called the Solar Minimum. The intensity of the maximum and the calm of the minimum can vary, but the cycles themselves are very evident.
As for why you occasionally see the sun’s orb shake in the frame, or see momentary frames of darkness throughout the video, NASA has a very good explanation:
While SDO has kept an unblinking eye pointed at the sun, there have been a few moments it missed. The dark frames in the video are caused by Earth or the Moon eclipsing SDO as it passes between the spacecraft and the sun. A longer power outage in 2016 was caused by a temporary issue with the AIA instrument that was successfully resolved after one week. Images where the sun is off-center were observed when SDO was calibrating its instruments.
Observing the sun and keeping track of how active or inactive it is can be vital in predicting things like solar storms and other space climates that can affect Earth. When the sun throws plasma into space, charged particles reaching Earth can damage communication satellites and even jeopardize space missions.
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