Time is a very slow thing when we talk about the universe. Stars can live for many Billions of years, and over human timescales they seem stagnant and unchanging. So it’s no surprise that when we look at distant galaxies, they don’t appear to change at all over the course of centuries. But appearances can be deceiving. Galaxies do change, more quickly than you would imagine. M87, pictured above, is a monstrous Galaxy of nearly 1 Trillion stars, more than twice as populous as the Milky Way. It looks like a big fuzzy star, and it quite regular in appearance...