Барбара

20,000 years ago, a quarter of the landmass was covered in ice. An ice core is like a calendar: each layer represents a year, and the trapped air is the atmosphere of that time. Sea levels were about 120 meters lower than they are today. What glaciers are losing today took millennia to do.

Our Sun orbits the center of the Milky Way in about 240 million years. A telescope collects light that has been traveling for millennia. It remains dark in the control room—any stray light would ruin the image. Before sunrise, the galaxy is at its lowest point above the horizon.