Did you notice that the flaming ball of gas in the sky is getting larger?
Probably not, it’s been doing so since last July. Plus, it’s only increased a few percent in size — much less than the size changes we get throughout the day due to the distorting effect of our atmosphere.
But 4 January 2014 marks perihelion — the point of the Earth’s elliptical orbit around the Sun where the two bodies are closest to each other. At this point, the Earth’s core is a mere 147,098,161 kilometres from the centre of the Sun.
The opposite side of the orbit, when the Earth is furthest from the Sun, is known as the aphelion and occurs in the first few days of July when the average distance is 152,097,700 kilometres.
The exact date of perihelion is slightly different every year, due to orbital wobbles caused by the Moon. It was 2 January in 2013 and 5 January in 2012, and in 2015 it’ll be 4 January again. But it’s always in the first few days of the year — something we’ve known since Johannes Kepler published his laws of planetary motion in the early 1600s.
Does this affect you? No. Not really. Unless you’re a professional astrophysicist, or the precise size of the Sun in your holiday snaps bothers you. Is it still pretty cool? Definitely.
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