The Sun newspaper carries a report about the winter solstice but makes a common blunder about the summer solstice. One may forgive others being wrong, but The Sun about The Sun?
Its article today explains: “The winter solstice is on December 21 (TODAY) and is the “shortest” day of the year and marks the start of the winter period. This is because the tilt of the Earth’s axis is least aligned with the sun, providing us with the least daylight of the year.”
However it goes on to say: “The date where Earth is the nearest to the star is marked by the summer solstice.” This is wrong. It is a common mistake. The Earth is nearest the Sun in the northern hemisphere’s winter (now) and it is furthest from the Sun during the northern hemisphere’s summer in June. It is ‘counter-intuitive’ only for those in the northern hemisphere, but not for those in the southern hemisphere, where the Earth is nearest the Sun during the southern hemisphere’s summer (now) and furthest from the Sun during the southern hemisphere’s winter in June. This is an example of ‘observer bias’.
The season is determined by the Earth’s tilt and not by its distance from the Sun. A solstice is a time in its yearly orbit when the Earth’s axis points directly towards the Sun. The axis is the line directly through the centre of the Earth from the north to the south pole, around which the Earth spins. As it is tilted about 23 degrees from the ‘vertical’, it points directly towards the Sun twice a year, when the northern hemisphere is pointing to the Sun in June and when the southern hemisphere is pointing towards the Sun in December. However, as the Earth’s orbit is an ellipse and not a circle, it is, in fact, closer to the Sun in the northern hemisphere winter rather than its summer.
Technically, the winter solstice begins on December 21 at 4:28 p.m. Universal Time, so I have rushed to publish this blogpost exactly at 4:28 p.m.