Why is that this sun spacecraft picture blinking?
Have you ever ever visited EarthSky’s each day sun news post? It’s quite a lot of enjoyable. It adjustments every day as exercise on our native star waxes and wanes (and is particularly enjoyable this 12 months as a result of we’re at or close to the height of the sun’s 11-year cycle). And we frequently embody a video presenting spacecraft photographs of that day’s sun. However generally – as within the picture at prime – we encounter sun photographs made by spacecraft that seem to blink on and off or go darkish in locations. What the heck? Why are they blinking?
Join us keeping these daily updates on the night sky going. Donate now! We need you.
A blinking sun
The picture at prime was close to the tip of our sun news video for March 28. It’s fairly noticeable on that video, as a result of we used the identical sun picture a few occasions in a row. It’s also possible to see it within the picture on the prime. See the way it briefly flashes to black a few occasions? We requested our resident sun skilled – heliophysicist C. Alex Young of NASA Goddard Spaceflight Middle in Baltimore, Maryland – a member of EarthSky’s sun group and co-author of every day’s sun put up – to elucidate. He mentioned:
The information come down from the spacecraft in a stream that’s then processed in predefined chunks. Afterward, the information are transformed into photographs. The information streams are segments of a picture. They correspond to blocks throughout the picture. Generally a part of a stream will get corrupted, in order that, initially, when a block is transformed, it comes again as clean (or black). A part of the explanation the information come again in blocks is to reduce this impact. Often, any blanks are corrected for by the point the ultimate information are processed.
However some photographs are the primary preliminary quick processing, to get the information shortly. So that you would possibly see some fast blinks to black photographs, inside a sun animation, for that motive.
Under is a person picture from the sequence within the March 28 prominence picture, cropped to concentrate on the prominence. So, you’ll be able to see right here that crop contained the one dangerous block, which is black.
In order that’s the explanation!
Extra from Alex
Moreover working at Goddard Spaceflight Middle, and co-writing EarthSky’s each day sun put up, Alex and his spouse Linda run a web site referred to as TheSunToday.org. Right here’s extra from Alex on the corruption you would possibly see in photographs from sun-observing spacecraft:
Generally you will note these within the Giant Angle and Spectrometric Coronagraph Experiment (LASCO) photographs on the SOHO spacecraft. I realized about this as a result of I labored for SOHO. Again then, my job was to rewrite a few of the code that processed Excessive Ultraviolet Imaging Telescope (EIT) photographs from one working system to a different.
EIT is without doubt one of the precursors to SDO’s AIA instrument. AIA stands for Atmospheric Imaging Meeting. It’s really 4 telescopes designed to {photograph} the sun’s floor and environment. And it was SDO AIA that created the picture above.
Thanks to your data, Alex!
Backside line: Generally, we see a sun spacecraft picture that appears to blink on and off. This occurs when a spacecraft sends again an information stream the place a few of the information are corrupted.
