US-Russia separated by only 3.8 km but 21 hours, How?

The two superpowers Russia and US, despite looking far away, are only 3.8 km away, but the time difference between the two is over 21 hours. 

If you look at the world map, you will feel that the United States of America and Russia are far away from each other, in fact, they seem to be on opposite sides of the world. But in reality, they are just 3.8 km apart.

According to alaskacenters.gov, the smallest distance between mainland Alaska mainland Russia and is approximately 88.5 kilometres (55 miles).

But, an island in the Pacific ocean separates the two countries by a mere distance of 3.8 kilometres (2.4 miles).

Bering Strait located in the Pacific Ocean is the closest geographic point between the borders of the USA and Russia. Big Diomede and Little Diomede are two small islands in the Bering Strait, that are just 3.8 km away from each other.

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The Little Diomede island is owned by the US, while Big Diomede is the property of Russia.

Interestingly, despite being so close to each other the two islands have a time difference of 21 hours. Big Diomede is 21 hours ahead of Little Diomede.

Due to this reason, the island Big Diomedes is also known as Tomorrow Island while Little Diomedes is also known as Yesterday Island.

Surprisingly, during the winter, the water between these two islands actually freezes over. So, if you were to walk from the US to Russia on this seasonal sea ice, you would literally be walking into the next day. However, travelling between the two islands is not allowed by the US and Russia.

Alaska, in 1867, was purchased by the United States from Russia and a new border was drawn between the two islands.