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by Dr. Tony Phillips
July 16, 2021
from SpaceWeatherArchive Website
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 The July 13th CME

Imaged by SOHO coronagraphs
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Imagine an explosion on the far-side of the sun so powerful, we could feel it here on Earth. It happened on July 13th...

The debris emerged in a circular cloud known as a 'halo CME' (above image).

When space weather forecasters first saw this explosion, there was a moment of excitement.

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It appeared to be heading directly toward Earth.

However, data from NASA's STEREO-A spacecraft indicated otherwise.

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The CME was heading directly away from us - a far-side event.

Now for the interesting part:

Although the explosion occurred on the far-side, separated from Earth by the massive body of the sun, it still peppered our planet with high-energy particles.

The Energetic and Relativistic Nuclei and Electron (ERNE) detector onboard SOHO recorded a surge in radiation not long after the CME appeared:

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How did this radiation reach Earth?

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Rami Vainio, a professor of space physics at the University of Turku (Finland), who works with ERNE data says,

"it's not possible to answer that question definitely without a detailed analysis involving multiple spacecraft."

However, he speculates that the lift-off of the CME may have created a global shock wave on the farside of the sun.

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Particles spilling over the edge might have spiraled toward our planet.

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Of particular interest are the green data points (51 to 100 MeV).

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These are the most energetic protons ERNE can detect. An uptick in green after the CME indicates unusually "hard" radiation - the kind accelerated in the leading edge of a fast-moving CME.

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The source of the blast might have been the same sunspot (AR2838) that produced the first X-flare of Solar Cycle 25 on July 3rd.

That sunspot is currently transiting the far-side of the sun approximately where the CME came from...

Within the next week AR2838 is expected to return - and then, maybe, the real fun begins...

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