Aliens could say hello by arranging planets in prime number pattern

A sufficiently advanced alien civilisation would be able to arrange the orbits of the planets in its star system in a pattern that could never form naturally, signaling its existence to others

By Jonathan O’Callaghan

What would be the best way for an advanced alien civilisation to make its presence known across the galaxy? It might be to make the planets in its star system dance in mathematical sequence.

Many searches for intelligent life have been conducted to date, such as looking for radio signals or even megastructures surrounding stars, but the results from these can be ambiguous and have potential natural explanations. That is why Sean Raymond at the University of Bordeaux, France, and his …