You can hear a blue whale's heartbeat from two miles away.

The blue whale is the largest animal on the planet, weighing up to 150 tons and measuring up to 90 feet long. Naturally, an animal this massive would have an equally huge heart. Roughly the size of a small car, the blue whale's heart weighs about 1,300 pounds. To move blood through its colossal body and arteries, its heart beats so powerfully, you can hear it from two miles away. You just might miss it, though, as its heart only beats eight to 10 times per minute.