Drake equation applied to dating geologic time scale and relative dating lab
How many stars have planets is unknown, mostly because we are only now developing the technology to find Earth-sized planets around other stars.
According to the Scientific American, recent estimates are that 7-30% of stars have planets large enough for us to detect them (roughly Saturn-sized or larger).
There is no scientific consensus on the exact process by which this happened in the first place, so there really is no way of knowing how likely it is to occur somewhere else.
However, this is another variable which Rich Townsend says is effectively 100%.
What percentage of intelligent civilizations will never invent them, or, having invented them (at least theoretically), decide never to use any with sufficient power to broadcast radio waves out into space.The second variable, f(I), is far more problematic.This variable refers to the likelihood that intelligence will evolve.The Milky Way Galaxy currently holds about 100 billion stars.This is the only function in the Drake Equation that can be known with any degree of mathematical certainty.
If that weren’t the case, life simply wouldn’t have time to evolve far before one or another stellar or natural disaster simply wiped it all out.