And the odd mix of radioactive elements caused their sun to start oscillating in intensity destroying every planet that previously held life in their solar syst

And the odd mix of radioactive elements caused their sun to start oscillating in intensity destroying every planet that previously held life in their solar system... One of the great filters. Fun speculation aside, I would love to see this as the target of a gravitational telescope. If that oscillation is stable it would be an interesting periodic driver of evolution. Like so many species on earth have evolved through optimization of day/night/tidal/seasonal periodic effects.