Could a solar flare be coaxed from a star with a magnetic weapon, possibly by manipulating magnetic reconnection? Could the resulting flare be aimed at a planet (or space fleet) with any accuracy?

I understand that a solar flare will not "fry" a planet, but I am hoping for a portable weapon that would cause extreme mayhem and disruption (not planetcide). By portable, I mean it can be transported and deployed from a ship, or the weapon is the whole ship.

A NASA video about the coronal mass ejection event in 2012 suggests that repeated flares, or co-ordinated flares could be more damaging. Could this weapon (or ship) survive the flairs or possibly get out of the way to fire again and again?

Technology level is thousands of years in the future. My story is set in an Electric Universe where electromagnetism is a stand-in for magic, but I'd like to get a reality-check before I add the handwavium.

  • 1
    $\begingroup$ I don't think solar flares are triggered by magnetic fields in the star, but produce magnetic fields as a by product of the flare. The birth of a flare is from turbulence below the surface of the star. The turbulence generates a field which draws star material outwards which we see as the flare. $\endgroup$
    – Reactgular
    Commented Jun 5, 2017 at 19:26
  • $\begingroup$ Traditional natural flares aren't entirely magnetic in nature, no. Magnetism does play a part in them obviously. But for the sake of him trying to weaponize ejected solar material, the only way to induce it is with magnetism or extreme temperature differentials, the latter being questionable to achieve artificially. $\endgroup$
    – Cereza
    Commented Jun 5, 2017 at 19:39
  • 2
    $\begingroup$ FYI, in Larry Niven's Ringworld series, the builders of the Ringworld used such a system to make solar flares LASE (as in laser), to vaporize meteors and wayward spacecraft. $\endgroup$
    – Catalyst
    Commented Jun 6, 2017 at 12:24

5 Answers 5


Solar flares are "quite energetic" phenomena.

If your civilazation has enough energy to trigger/control a solar flare, I would better bet on using that energy directly on the enemy, rather than steering it to the Sun and let the Sun do the hit.

What I mean, if you have a nuke, you don't use it to fire a potato cannon and hit your enemy with a potato...

  • $\begingroup$ Hahaha potato cannon! $\endgroup$
    – wetcircuit
    Commented Jun 6, 2017 at 18:46

Absolutely, though it's quite an undertaking. The scope of it has nothing to do with how advanced you are so much as the scope of weaponizing such a thing.

The easiest way to do this would be to build statite magnetic panels around the sun (statites being light sail material that floats on the photon pressure from the star). Get these in a speedy orbit, and oscillate their distance closer and further from the star.

The plasma of a star is already severely polarized, so this would drive the plasma in two directions away from the star. Coronal ejections would have nothing on the barrage of stellar material this would eject.

It's easier to eject this material from the north and south poles of the star, but you could do it off points along its equator or the like, to hit planets as well.

A more advanced concept is the Nicoll-Dyson beam, though it's a lot more work, to the point the inhabitants of the planet would have time to stop you likely.


I second (third) the posts saying no.

In addition to the stated issue, that solar flare takes a massive amount of energy to produce, it does no noticable harm to a planet. The flare is so far away from a planet that the energy that reaches the planet is a very tiny fraction of the energy produced from the flare.

The real problem is two fold.

  1. your not going to be able to get any more energy out of a solar flare then you put into it
  2. the distances between sun and planet, coupled with exponential decrease in energy, means far too much energy is wasted in travel.

The solution then seems simple, ignore the solar flare entirely and use the energy directly near the planet.

Get up close to the planet and use your energy up close and personal to ruin the day of people on the planet. You can simply project large masses at the planet (so long as the mass/meteor you find as a metal core electromagnetism can be used to accelerate it). If you want something less lethal consider an EMP pulse to wipe out technology, with the ship firing the pulse either being shielded or moving away from the 'bomb' it plants before it's set off.

In any case it makes sense to exert your energy up close and personal then at such a massive range as the sun.


Realistically, no

You asked for a "reality check" so I have to say: no. You, a puny human, cannot weaponize solar flares. You cannot even affect them in any significant way.

As this video shows, solar flares are mind-bogglingly huge. The largest human-made structure is not even one millionth of the size of one pixel in that video. The largest ever energy excretion made by humans — the Tsar Bomba — is 1 / 10 000 the energy content of an average observable solar flare.

As a single human being, even with all the realistically available resources at your disposal, your can affect a solar flare pretty much in the same way as you can affect the Atlantic Ocean, which on the whole is: not at all.


The truth is that we still don't know.

I'm pretty sure that a thousand years ago, nobody would find reasonable, with their knowledge, that humankind could devastate what they would consider at time, something like half the world, with a object not much bigger than a elephant. They would clearly find it to be some kind of magic.

I believe I got where you are trying to go.

Probably, our apice of energy production as a civilization, will be some kind of efficient harvesting from stars and other energetic objects on our vicinity itself... It is reasonable to believe that, when (or if...) we get to be a civilization of type II in terms of Kardashev scale we may discover ways to build devices nearby sun that can use its energy to exploit solar flares itself in a controlled manner, as a weapon, among much other things, such as adjustments on the entire solar system trajectory inside Milky Way, etc.

But, there exist other theoretical concepts that sound more reasonable, effective and efficient.

For example, a huge net of big scale mirrors near sun, that can be adjusted to concentrate a reasonable amount of energy from sun into any point inside solar system.


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