Solar flares and lightning strikes are both kinds of electric discharges.

A lightning strike is a sudden discharge of electrical energy between an electrically charged cloud and another object, like the ground or another cloud.

A solar flare is a sudden discharge of electrical energy between two electrically charged regions, or "clouds" in the atmosphere of the sun.


A lightning strike lasts about 0.2 seconds, and it is made up of a series of short strokes of about 60 to 70 microseconds each. It produces an electromagnetic pulse (EMP) that consists of electromagnetic radiation across the spectrum from radio to gamma waves.

A solar flare lasts on the order of minutes to tens of minutes, and is also comprised of series of short bursts. This video of the Cinco de Mayo solar flare shows the way that the solar flare is comprised of multiple short discharges of electromagnetic radiation, which can be seen in the visual spectrum and also detected in other wavelengths like radio, ultraviolet, and x-ray, and gamma.

Amount of energy

  • Large lightning strike: 109 joules
  • Large solar flare: 1025 joules

Some other gifs of solar flares

Relevant links

Related questions

My question

I'm also wondering if a solar flare is an electrostatic discharge. My main question is:

If we were to make an oversimplification about solar flares, would we say that they are big lightning strikes on the sun?

  • $\begingroup$ This is more a question of semantics than astronomy. $\endgroup$
    – eshaya
    Commented Apr 27, 2021 at 14:22
  • 1
    $\begingroup$ Does this answer your question? Can lightning occur in stars like the Sun? $\endgroup$
    – WarpPrime
    Commented Apr 27, 2021 at 15:30
  • $\begingroup$ Other than semantic, a solar flare involves mass, it is not just an electron/current flow. It depend on what have you in mind, but it does not seem a particularly fair description. $\endgroup$
    – Alchimista
    Commented Apr 28, 2021 at 10:13
  • $\begingroup$ Lightning strikes and solar flares both involve charged particles, having mass, translating between locations at relativistic speeds. A solar flare is a little bit like an electrostatic discharge in this sense. This brings another question to mind: How much mass is in the electrons in the current of a lightning strike? $\endgroup$
    – Heyzeuss
    Commented Apr 29, 2021 at 6:54
  • 1
    $\begingroup$ @Iktys perhaps I have been imprecise. But the meaning is that in a strike you do not have electrons or ions from the cloud reaching the ground or viceversa. It is electrical current. A solar flare ejects and transports mass from a point to another. $\endgroup$
    – Alchimista
    Commented Apr 29, 2021 at 9:27

1 Answer 1


ProfRob gives a more detailed explanation of what a solar flare is in his answer to "What triggers a solar flare?" It helps a lot in distinguishing between CME's, eruptions, prominences and solar flares. There is a lot of confusion, even among space enthusiasts, between these phenomena. This is largely because images of prominences and CMEs always seem to be labeled as solar flares. This has been confusing to me, too. A solar flare might be associated with a large eruption of matter, but that is secondary, and the primary feature of a solar flare is plasma being suddenly moved from one location to another by magnetic reconnection, causing it to collide at relativistic speeds with the chromosphere and photosphere, producing the intense light and x-rays seen from earth. Unlike lightning, a solar flare is not an electrostatic discharge. A solar flare is like lightning in the sense that there is a near light-speed flow of charged particles that result in the emission of bright electromagnetic energy, spanning the entire spectrum from radio to gamma waves.

  • $\begingroup$ “a near light-speed flow of charged particles” in a lightning? oRLY? $\endgroup$ Commented Jul 31, 2021 at 17:52

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