Karre's X-wing crashes into Tatooine at incredible speeds. Although it's damaged, it manages to maintain its general shape, and isn't instantly vaporized. This is important to remember as earlier Am tears the kyber-crystal right out of Karre's X-wing. The diameter of Tatooine is 10,465km.
T = 1s/24
= 41.6666667ms X 2
= 83.3333334ms + 1s
= 1.08333333s
395 pixels = 10,465km
1 pixel = 10465km/395 = 26.4936709km
26.4936709km X 258 = 6835.36709km
T = 6835.36709km/1.08333333s
= 6309569.64/340.29
= Mach 18541.7427
Now we have the speed, let's find the kinetic energy. X-wings weigh 10 metric tons (or 10,000kg).
KE = (0.5)mv^2
= (0.5) X 10,000 X 6309569.64^2
= 1.99053345e17 joules
= 47.574891252390060004 megatons
That's not all though! Karre himself is outside the X-wing cockpit. Meaning he'd have to withstand that kinetic energy too. The average global weight of a man is 136.7 pounds, or 62.006077kg.
KE = (0.5)mv^2
= (0.5) X 62.006077 X 6309569.64^2
= 1.23425171e15 joules
= 294.9932385277246567 kilotons
Final Results
Karre's X-wing crashes into Tatooine (speed) = Mach 18541.7427
Karre's X-wing crashes into Tatooine (energy) = 47.575 megatons
Karre's kinetic energy = 294.993 kilotons