Far more serious than beaming a salted snack advert into space, scientists at Pennsylvania State University in State College suggest that if we really want to catch the attention of aliens, then we should cover half the moon in mirrors, and send coded flashes of light into space. Always assuming ET's not too bored by us, that is.

Properly angled and lined up to reflect light from the sun, the mirrors could be used to increase the amount of light reflected by the Earth-Moon system by up to 20%. Any alien eye scanning the heavens—or, more likely, an automated system like SETI set up by aliens—should be able to easily spot the modulations. A set of prime numbers in flashes would be a good choice, since these are easily distinguishable from natural variations. Furthermore, pop photovoltaic cells on the other side of the mirrors, beam the energy to Earth by microwaves and you'd have enough power to seriously impact the climate crisis. Not a bad idea, eh? [New Scientist via KurzweilAI]