关于这张图
Panta rhei is a simplified version of the famous Greek philosopher Heraclitus' teachings. It basically means, everything flows. And everything in the Universe is indeed continually on the move, spiraling and shifting through space. Some cosmic objects move a little further than others — take the subject of this NASA/ESA Hubble Space Telescope image, a globular cluster of stars known as Palomar 12. Although it currently lies on the outskirts of the Milky Way’s halo, Palomar 12 was not born here. When astronomers first studied this cluster, they were puzzled by its strangely young age when comp…
