"According to the idea, the solar system had its origin in a gigantic star into which a smaller, dead, waterlogged star fell. This impact caused a huge explosion which flung fragments of the smaller star out into interstellar space where the water condensed and froze into giant blocks of ice. A ring of such blocks formed, which we now call the Milky Way, as well as a number of solar systems among which was our own, but with many more planets than currently exist."

maybe too far fetched? If it was like that we would have already spotted similar galactic formations outside of the Milky Way