pale.emperor said: This particular lecture explained about our galaxy, and how it's only one of billions in the universe.
Some of my fave websites are Nasa's. Their Kepler Mission has so far discovered 20 other candidate planets, besides Earth, in the habitable zone of stars ( https://www.nasa.gov/feature/ames/kepler/astronomers-help-focus-research-in-the-search-for-another-earth) nine which have been previously investigated and determined to be verified planets, including notables like Kepler-62f, Kepler-186f, Kepler-283c, Kepler-296f and Kepler-442b.
Knowing that amino acids, the building blocks of proteins/life, have been found in meteorites that have landed on Earth, it is not a far reach at all to conclude life could very well exist elsewhere in our Universe.