Besides looking at other planets, we have satellites observing Earth, too. From those images, here's the life thus far of an Antarctic iceberg the U.S. National Ice Center calls B31. You can follow along in the NASA Earth Observatory images below.

The iceberg separated from the Pine Island Glacier in November, 2013, and has slowly made its way out of a bay and in April had closed in on the southernmost shipping lanes of the world.

During that time, it has gotten a little smaller than the photo at the top of page, but it's still 255 square miles in size. As a comparison, Flathead Lake is about 199 square miles in size. The iceberg is about 50 percent bigger than previous icebergs in the same area, according to NASA.

B31 is very thick and the deeper ocean currents are expected to play a big role in where it goes.