How many galaxies are there? 

There are about 80-100 billion galaxies in the observable universe, that is, that part of the universe visible to us. There may be more in that part of the Universe beyond our observable limit, which occurs about 400,000 years after the Big Bang. Before that time, the universe remains opaque to us. It's like trying to see through a dense fog. After this time, the "fog" lifted and light could traverse the universe. This occurred because the universe expanded and cooled, allowing electrons to pair with protons and light to travel without bumping into the free electrons.

The mind blowing thing to think about is all the stars in these galaxies… Our Milky Way has roughly 200 billion stars. While we've discovered over 300 planets outside our Solar System, the galaxy must be filled with trillions of planets. Now think about each of those 100 billion galaxies in our observable universe. Each has hundreds of billions of stars and probably trillions of planets too. Do any of them harbor life? We do not know, and we may never know. But we continue to look.