WHAT HAPPENS IF TWO PIECES OF METAL TOUCH IN SPACE ???

 If we take two pieces of metal of same type in space then they will fuse together.

This process is known as "Cold Welding" 



Why it's some how impossible on Earth???

Due to presnce of oxygen in Earth's 🌍atmosphere ,thin film of oxide is formed over the metal surface which act as a barrier that prevents the metal lump from sticking to other lump of metal.

Whereas in vacuum of space, no oxide layer formed , so there is no blockage and metal atoms between the two surfaces form new metallic bonds, removing the two original surface.



Now you might be thinking what happened to metal tools used by astronauts🤔

This effect isn't an issue for astronauts because the tools they use retain the protective oxide layer it had on Earth.

However, the process doesn't happen instantaneously but require time, pressure and vibration..