The post clarifies the distinction between a planet's rotation period and its day length, emphasizing that for planets like Venus and Mercury, these can differ significantly. It explains the calculation of a day length and examines prograde and retrograde rotation, revealing misconceptions found in popular science.
In approximately 1.3 million years, Gliese 710 will approach the Solar System at a distance of 0.166 light years, the closest known encounter. This orange star, significantly less luminous and cooler than the Sun, could disrupt the Oort cloud, potentially sending comets toward Earth and increasing the risk of impact events.
With all the events going on in the world it passed almost unnoticed that a decision was made recently to abolish the leap second. The resolution was made on 18 November 2022 during a meeting held in Paris held by the International Bureau of Weights and Measures. What is a leap second? The length of… Continue reading No more leap seconds
Updated 16 December 2025 Even though the Moon is far smaller and less massive than the Earth its gravitational field still has significant effects on our planet. The most noticeable of these are tides, the periodic rise and fall of sea levels. In this post I'll give an overview of the causes of tides. This… Continue reading Overview of tides
Polaris, commonly known as the pole star, is situated near the North Celestial Pole and has been used for centuries for navigation. But Polaris hasn't always been the Pole Star and won't be in future. This is gradually changing over a 25 800 year cycle.
