If you travel from New York to London, it will take around six hours, but when you travel from London to New York, it invariably takes significantly longer.

There is an urban myth that the shorter trip is caused by the rotation of the Earth; that since the Earth rotates eastward, planes heading west will travel faster as the planet rotates beneath the aircraft. This is not true since every part of the planet is being rotated eastward, including the atmosphere and the planes flying within it.

The real reason flights from west to east are quicker is down to jet streams. Jet streams are high-altitude winds that blow from the west to the east across the globe. The speed of these winds can be as high as 200mph (321km/h) and they help regulate climate all over the world. Airplanes fly into the jet stream at 30,000 feet and then travel with these winds. Since the jet stream winds go from west to east, airplanes flying eastward can take advantage of the fast moving winds and hitch a ride on this atmospheric river. However, a plane flying to the west would be going against the winds.

There are five jet streams on planet Earth. Most airplanes are affected by the polar jet stream at an altitude of 9-12 km near the north pole. Polar jet streams are the fastest.