Around a million, billion neutrinos from the Sun will pass through your body while you read this sentence.
A nutrino is a neutral sub-atomic particle of such small mass that it passes through matter undisturbed.
Its mass has never before been measured accurately and this picture is a device that was set up to detect nutrinos, as VERY ocasionaly they will colide with matter producing energy in the form of light/heat. but this energy is so small that it is virtually undetectable.
Nutrinos are formed from redioactive decay, or nuclear reactions, which is why the sun gives of so many.