In 1920, astronomers Harlow Shapley and Heber Curtis held a Great Debate. Shapley argued that the spiral nebulae were small and in the Milky Way, while Curtis took a more radical position that they ...
The materials that make up your body are intergalactic voyagers that have existed beyond the limits of the Milky ... way around" the galaxy before coming together to make up our bodies here on Earth.
Milky Way May Have Billions of Earth-Like Planets There could be as many as 40 billion habitable Earth-size planets in the galaxy, according to a new study. WSJ's Monika Vosough reports.