Earth's orbit around the Sun is slightly elliptical, which means our distance from the Sun varies over the course of the year – and that brings effects that are fascinating to capture.
The variation sounds quite impressive: Earth swings from 147,099,894km (91,403,636 miles) from the Sun in early January, to 152,087,774km (94,502,961 miles) in early July, a difference of 4,987,880km (3,099,324 miles) – small in astronomical terms, but you wouldn't want to walk it!
Tracking time and size
In an elliptical orbit, an object moves fastest when closer to its star, and Earth is no exception. This affects the apparent speed of the Sun across the sky: slightly faster at the start of the year and slowest in the middle. This makes timekeeping based on the position of the Sun…