A Blue Whale's Heart Is the Size of a Small Car

Blue whales are the largest animals ever to have existed on Earth ? longer than two city buses end-to-end, heavier than thirty African elephants. Everything about them is spectacular in scale. But their heart deserves its own headline.

A blue whale's heart weighs roughly 400 pounds, about the same as a large motorcycle, and is approximately the size of a small car or a very generously proportioned golf cart. Its main artery ? the aorta ? is wide enough for a small child to crawl through. For comparison, your aorta is about as wide as a garden hose. Theirs could fit a golden retriever, comfortably.

Here is where it gets weirder. When a blue whale dives deep, its heart rate slows to just two beats per minute ? a dramatic drop from around thirty beats at the surface. Scientists first confirmed this in 2019 by attaching suction-cup sensors to a living whale off the California coast. The data revealed one of the most extreme heart rate swings ever recorded in any animal. Two beats per minute. That is basically a very polite knock at the door.

If you listen closely to the ocean with the right equipment, you can actually detect a blue whale's heartbeat from some distance away. It is slow, powerful, and completely indifferent to your schedule. As far as hearts go, the blue whale's is the undisputed heavyweight champion ? and honestly, it probably does not even know it.