First a short lesson on kinetic energy. (Mass x Velocity^2)/2
At 20 kilometers per second (high to typical asteroid impact velocity) a kilogram of mass has 200 million joules of energy.
(1 X 20,000^2)/2
At 500 kilometers per second (upper end of interstellar asteroid impact velocities, near worse case) a kilogram of mass has 125 billion joules of energy.
(1 X 500,000^2)/2
Twenty five times the velocity means it has 625 times more energy.
One megaton is equivalent to 4.18 x 10^15 joules
One megaton will raise the temperature of a 1 kilometer cube of water by about 1 degree Celsius.
At 20 kilometers per second (high to typical asteroid impact velocity) a kilogram of mass has 200 million joules of energy.
(1 X 20,000^2)/2
At 500 kilometers per second (upper end of interstellar asteroid impact velocities, near worse case) a kilogram of mass has 125 billion joules of energy.
(1 X 500,000^2)/2
Twenty five times the velocity means it has 625 times more energy.
One megaton is equivalent to 4.18 x 10^15 joules
One megaton will raise the temperature of a 1 kilometer cube of water by about 1 degree Celsius.