Formation of Galaxies

Are We Alone in the Universe? The Surprising Probability of Alien Life In this short video, we learn about the mind-blowing number of potential Earth-sized planets that may exist in the universe. According to recent studies, on average, every star has at least one planet, and one-fifth of those have Earth-sized planets. With approximately 100 billion stars in our Milky Way galaxy alone, this means there could be billions of Earth-like planets in our galaxy. And when you consider the 100 billion

Some galaxies, like... - Space Telescope Science Institute