[kahljorn]

u can do it with any lightwave but i think they use ir/visible in space (for planets and stuff anyway for stars u could probably use xrays if u used the telescopes in space). also i think xrays would be bad (for planets) since they are one of the lightwaves that penetrate atmosphere the least.

but yea its called spectroscopy

and no he means some futuristic invention that will rely on some kinda super quantum particle or something thats able to penetrate through planets and carry all of the information with it and a futuristic device will translate that and tell you everything about the planet