1021 meters = 1,000,000,000,000,000,000 kilometers
Seen from high above, the Milky Way galaxy resembles a pancake with a bulge at the center. The pancake is about 100,000 light-years in diameter. The sun is 26,000 light-years—or about two-thirds of the distance—from the center of the pancake. In this part of the galaxy, the Milky Way is about 3,000 light-years thick.
The stars in our galaxy orbit around its center in much the same way the planets move around the sun. But they actually bob up and down—like horses on a merry-go-round!
The time it takes for a star to make one trip around the galactic core depends on its distance. The sun, moving at 250 kilometers (150 miles) per second, takes a whopping 220 million years to make one trip. The sun, and hence our solar system, has made fewer than 25 such journeys since its hydrogen-fusion fire ignited.