The original post: /r/askscience by /u/tacertain on 2024-12-14 18:18:37.

From this article:

“The team noted that the strongest impact in this brief record is the Carrington Event, a massive solar storm in the year 1859 that reached a total energy exceeding 10³² erg (an erg is a very small unit in the centimetre-gram-second system for measuring energy; there are 10 million ergs in one joule).”

Looking around a little, it seems that solar flare energy is always measured in ergs even though the range of energies is orders of magnitude greater than a joule. Why use ergs?