A City of Stars

My love of globular clusters is on record. Of all the objects in the deep sky--that is, outside our solar system--they are the ones that, through a telescope, look most like what they're supposed to look like. Nebulae are great, and so are galaxies, but when you look at them through an eyepiece of a typical small telescope you usually only see a faint smudgy thing. But when you get a globular in the crosshairs, you see it. Thousands of stars packed together so tightly that the center looks like ...