The one way to discover about aliens is to tune your radio telescope and listen to the signals.

Let me mention that not all sun-like stars host planets - perhaps about 30% of them are planet-builders. It's not so easy to form a planet!

It's not very fun to do spectroscopy.

There are many unidentified bands in the spectra of stars. Wide bands are produced by some complex molecules in the interstellar space.

Spectroscopy can probably answer the question, 'Is there anybody out there?' Are we alone?

I have no doubt that Brian May would have had a brilliant career in science had he completed his Ph.D. in 1971.