@SalaHyena(View Post) -_- fusion is caused when atoms are under so much pressure and heat that they are forced to be 'squished' together. If you want a really really basic definition. but theoretically it can be done anywhere else with those conditions (like TPT :P). Mass has nothing to do with it.
heat & pressure -> fusion mass-> gravity
Would you like me to give you an in-depth explanation? >:)