Why are the Iliad and the Odyssey significant works of literature to the ancient Greeks? They were the first books ever written. They provided a guide for moral behavior. They were based on Western ideals. They explained how Greece could avoid foreign conquest.

When the indian plate collided with eurasian plate because it was cool 

1. why do astronomers think that there may be other advanced civilizations?
because  it was discovered that there are other planets like earth out there, able to  accommodate life forms.
2. what technologies are astronomers using to look for life on other planets? why?  
they  have used radio telescopes, but now they use laser telescopes   to track laser communications.