Answer:
1.) 36 alien civilizations could communicate with us.
2.) The nearest alien could be on Mars which is 54.6 million kilometers
away.
3.) No I don't agree. There could be millions of alien civilisations out there that we haven't found because space is so big.
The main reason would be the environment because of the fact their population is so big, they need enough room for everyone. There's also the connection with having available food source within the environment when the people plan to settle in. There's also the idea of desirable climate which helps them with food sources and allows them to flourish instead of dying off.