The Space Doctor on Instagram: "The creator and the destroyer. The Andromeda and Milky Way galaxies are expected to collide in about 4.5 billion years. Surprisingly the sun becomes a red giant in around the same time. So what's a red giant? When a star is about to die it increases in size, our sun will do the same. This happens before the Andromeda collides with our milky way to form Milkromeda. Is it a kind of backstab done by sun? Or something else. #space"

Astro Alexandra on Instagram: "A giant wave traveling through the Milky Way galaxy #space #astronomy #nasa #science"