Familiar as she is, the moon is very, very far away. She is 238,857 miles away, to be exact; a seemingly endless expanse of starry oblivion. If you could hop a nonstop flight to the moon, it would take you sixteen days to arrive. (You might want to spring for first class, no?) The Apollo 11 shuttle made it in only four days, but it was strapped with over 5.5 million lbs of rocket fuel.
Now imagine this: there is an animal that could fly to the moon and back over the course of its lifetime. In fact, it could make three round trips. It weighs less than 4 ounces. Its heart is the size of your knuckle.
It’s the Arctic Tern, and it has the longest migration of any animal. Living almost entirely on the wing, it travels from its breeding grounds in northern Greenland to its winter grounds on the shores of Antarctica and back – the only two times a year it lands. Of course, it doesn’t travel a straight line, but bounces between continents to take advantage of prevailing winds and abundant food sources, turning a 25,000 mile circumnavigation into a 44,000 mile annual epic. One tern fitted with a tiny tracking device was discovered to have flown 50,7000 miles in one year.
Again, it weighs less than 4 ounces. Its heart is the size of your knuckle.
The average lifespan of an arctic tern is 20 years, but it is not uncommon to find 30-year old terns. So while the average tern makes the equivalent of almost 2 round-trip lunar journeys, an extraordinary tern could fly 1.5 million miles in its life, or three times to the moon and back.
Why does it do it? Why does this tiny bird spend its life flying to the moon, traveling from the North Pole to the South, through storms and nearly endless expanses of featureless ocean?
To stay in the sun. Because it has the longest migration, the Arctic Tern also sees more sunlight than any animal alive. By alternating between the Arctic and Antarctic circles, the tern lives in a constant summer and, for half its life, constant daylight. By being at the right place – the extremes of the Earth – at the right time – the few weeks a year in which they are habitable – the tern can live and raise its young in relative safety and abundance, without many predators or much competition. To enjoy a little bliss, it will fly to the edge of the world. Then it will fly to the other edge of the world, and will call it worth it, to have had that peaceful, all-too-brief moment of sunshine to itself. The lengths to which life will go to be satisfied are astounding: to travel to the moon, in order to stay in a sun that will never set.