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[Ivan2006]

technically, you need to burn retrograde to the earth's orbit around the sun until your periapsis reaches into the corona.
I actually did some calculations, and if you want to crash into the sun (assuming my calculations are correct), you need to negate almost all of earth's lateral velocity, which is almost 30 km/s.
That is 10 times as much as is requires to get into a transfer orbit to mars.