Meteor speed and heat relation

For following calculations i used 2 calculators.

Speed-heat relationship was calculated with this calculator using iron (amu = ~56) and most probable speeds are mentioned here. Lighter elements are faster with same heat.

Calculator for finding relation between electronvolts and temperature.
Kinetic energy calculations were done with mass in kg times speed in meters per second squared.

From perspective of meteor the atmosphere would be coming towards meteor with approximately speed of meteor.

1000 C may be achieved at ~600m/s.
1510 C (melting point of steel) has atom speeds of 727 m/s. 
2750 C (boiling point of steel) at 945 m/s.
10 000 C at 1740 m/s.
Common orbiting objects move ~6-8 km/s and 7,7 km/s could heat iron up to 200 000 C.
Escape velocity is about 11 km/s and such objects could heat to 400 000 C. Obviously any satellite flying through atmosphere is highly likely to boil away to metal vapour unless it descents almost horizontally so it could slow down in thin atmosphere. 

Helios satellite may is one of the fastest satellites made with speed of 70 km/s which could heat up to 17 million C which in turn can be hot enough to cause x-rays (~1400 eV). It's mass is 370 kg so it has ~900 billion joules of kinetic energy. In comparison lightning strike can be 1 billion joules and 1,4 billion joules is theoretical minimum needed to melt ton of steel.

As humans can create satellites with such speeds it is possible that they may be used as weapons considering 1 ton of random material could release energy comparable to thousands of lightning strikes released within couple of seconds. Helios 2 took about 3 months to get close to sun and in this time in picked up speed partly from gravity of nearby massive bodies. Another way to get them fast would be to send a lot of rocket fuel in space and build a giant military "meteor" to speed up quickly (within hour) as rockets can reach from zero to orbiting speed in ~10 minutes.

Andromeda galaxy is moving towards milky way with speed of ~300 km/s. This could heat iron up to 3 billion degrees. While collisions may be unlikely due to huge distances between stars and planets it would still be destructive to galaxies to have such high intensity collision as those which happen are hot enough to create x-rays and gamma rays. 1 gram of matter moving with 300 km/s has about 45 gigajoules of energy and those on planets in colliding galaxies are likely to see even single grams worth of dust brighten the sky with ~50 lightning strikes worth of energy.

Antennae galaxies have been colliding long enough for widespread x ray production. Most of that skull shaped structure has huge patches where heat is high enough for x-ray production.
This may be also how Andromeda and Milky way start looking when their planets and stars hit each other so fast that their atoms fly apart in every direction with more than escape velocity. That leaves behind quickly expanding debris zones which may destroy other nearby stars and planets or at least heat atmospheres too much for life.

Also this 300 km/s speed may be enough to cause nuclear reactions. Stars that reach about 3 billion degrees burn silicon to iron and other metals. If tiny icy comet hit atmosphere at 300 km/s then small amount of it could turn to metals leaving behind cloud of metals and silicon. 3 billion degrees is about 0,25 MeV but each proton and neutron is bound to nucleus with up to ~9 MeV binding energy. Hydrogen fusion can happen at about 1 billion degrees so if those 2 galaxies met and 2 watery planets collided then they could release fusion energy.

To break apart all nucleons with ~8 MeV heat energy would need about 100 billion degrees and even metals could vaporize to hydrogen (protons) and neutrons. 100 billion degrees could be achieved with ~6000 km/s in case of iron.