Is it possible to fly around the equator non-stop and stay in daylight?
Theoretically it is possible but even a supersonic jet would be hindered by factors such as speed restrictions and in-flight refuelling.
Asked by: Andrew Robertson
Yes – but only in theory. The Earth is roughly 40,000km in circumference at the equator, and completes one rotation every 24 hours. This means that the Sun effectively zooms across the face of the Earth at the equator at around 1,700km/h. So you’d have to travel at least this fast to stay in daylight. But that’s around 1.5 times the speed of sound – and twice as fast as a conventional passenger plane.
In theory, a supersonic jet could manage it, but even then in-flight refuelling and speed restrictions over land would reduce the effective speed well below what’s needed. Not even Concorde managed it.
In August 1995, it achieved its fastest-ever circumnavigation of the Earth, and it still took more than 31 hours.
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Robert is a science writer and visiting professor of science at Aston University.