Imagine a heart so big that a grown human could crawl through its arteries—that's the incredible reality of the blue whale's heart! The blue whale, the largest animal on Earth, has a heart that weighs as much as an entire car—around 400 pounds (180 kg)! This massive organ pumps a whopping 60 gallons of blood with each beat, enough to fill a bathtub in one go.

The heartbeat of this ocean giant is so powerful that it can be heard from over two miles away. And when it beats, which is only about once every ten seconds when the whale is diving, it sends a pulse of life through a creature the size of a commercial airplane. Talk about a heart that’s got some serious strength!

If you think your heart is working hard, just remember the blue whale’s—keeping a 100-foot-long ocean behemoth running smoothly is no small task!