The elliptical nature of the Earth’s annual solar orbit means that there is one point, the Perihelion, when it is closest to the Sun. This occurred in 2024 at 00.38 GMT today (January 3^rd), when the centre of the Sun was just 147,100,632 kilometers from the Earth’s centre. Conversely, the point when the Earth’s orbit takes it furthest away from the Sun, the aphelion, will occur this year on July 5^th. The difference in distance between the perihelion and aphelion is around five million kilometers or, roughly, around 3% of the average distance of the Earth from the Sun.

The timing of these two points does not coincide with the winter and summer solstices, when the Earth experiences its shortest and longest days respectively. Scientists have calculated that the last time the winter solstice coincided with the perihelion was in 1246 AD. Since then, the date of the perihelion and aphelion has drifted away from the solstices at a rate of around one day every 58 years and between one year and the next the dates can vary by up to two days. By 6430 AD the perihelion will coincide with the vernal equinox.

Curiously, the average temperature of the whole Earth at the perihelion is about 2.3⁰C lower than at the aphelion, meaning that the planet is actually colder when it is closest to the Sun. On the plus side, according to Keppler’s Second Law, planets move more slowly at the aphelion than the perihelion, making the summers in the northern hemisphere two to three days longer than those in the southern.