SortStack #624 — 2028-02-23

By speed · Order from slowest to fastest.

1. A sea turtle cruising 3 km/h

   Sea turtles can hold their breath for hours while resting, slowing their heart to a beat every few minutes.

2. A gentoo penguin swimming 36 km/h

   Gentoos are the fastest underwater birds, porpoising in and out of the water to breathe without slowing down.

3. A charging black rhinoceros 54 km/h

   A rhino's horn is made of keratin, the same material as your hair and nails, not bone.

4. A charging lion 83 km/h

   Lions are the only big cats that live in groups, and a male's roar can be heard up to eight kilometres away.

5. A running pronghorn antelope 97 km/h

   The pronghorn can run far faster than any predator alive today, likely escaping a cheetah that went extinct in America.

6. A missile warhead on re-entry 24K km/h

   An intercontinental missile arcs into space before plunging back down, its warhead glowing from the friction.

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