I'm examining if a massive superflare early in the solar systems history could be the explanation for the odd positions of certain planets and moons in our solar system (and their rotations). For this test, i've taken Mars as an example. I’m going to place Mars in the early solar system in an orbit 80m Km from the sun and see if a superflare could blast it out to its current orbit in the solar system at 228m Km from the sun. For aesthetic purposes, here is a diagram of the famous XZ Tauri superflare superimposed (to scale) on our solar system: I’m going to do some very simplified calculations. Mass of Mars = 6.42 * 1023 kg. Mass of the Sun = 1.99 * 1030 kg. The kinetic energy of an orbiting body is KE = G(M*m/2r) where G is the gravitational constant, M is the mass of the body being orbited, m is the mass of the orbiting body, and r is the semi-major axis. Taking the proposed initial distance from the Sun of Mars as halfway between where Mercury and Venus currently are, so r = 8.31 * 1010meters. At this initial distance (I’m omitting writing units for the sake of clarity, but I have set everything to SI units) KE = (6.67 * 10-11)(1.99 * 1030 * 6.42 * 1023) / (2 * 8.31 *1010) = 5.13 * 1032 Joules. The current semi-major axis of Mars is r = 2.28 * 1011 meters. Solving for the current orbital kinetic energy, KE = (6.67 * 10-11)(1.99 * 1030 * 6.42 * 1023) / (2 * 2.28 * 1011) = 1.87 * 1032 Joules. The difference between these energies (simply 5.13 * 1032J – 1.87 * 1032J) is 3.26 * 1032Joules. So Mars would need 3.26 * 1032Joules of energy to move from its proposed initial orbit to its current orbit. Looking at https://en.wikipedia.org/wiki/Superflare (I couldn’t find a better source that listed superflare energies with actual numbers) I converted the highest energy superflare 2 * 1038 erg to 2 * 1031 Joules. This is the highest energy superflare they have listed (and it’s even a G type star like our Sun.) 2 * 1031 Joules is an order of magnitude away from the 3.26 * 1032 Joules needed to move Mars. For the sake of comparison, our Sun’s solar flares typically release around 1 * 1020 Joules of energy, the greatest of them releases 1 * 1025 Joules, and a million times the biggest events is only 1 * 1031Joules. Additionally, I did not even calculate the gravitational potential energy of Mars which would also have to be accounted for if we are moving from one orbit to another. Based on these calculations, I do not think a solar superflare would produce enough energy to move Mars. I guess an additional consideration with an event like this is the infinitesimal surface area of Mars compared to the fact that a superflare could be emitted in any direction, its energy spreads and decreases per square meter as it moves through space, and even an absolutely direct hit would only impart of fraction of the total energy of the superflare. So, is the proposal dead in the water? Superflares simply cannot move planets? Or am I missing something? I don't know if pressure radiation or gravitational waves could play a role. These are outside my area of expertise.