Astronomy Items
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.
The post explains that a year is defined by Earth's orbital motion around the Sun, encompassing three types: the sidereal year (365.256 days), the tropical year (approximately 365.242 days), and the anomalistic year (365.259 days). It discusses their lengths, differences, and the implications for calendars, notably the transition from the Julian to the Gregorian calendar to align with seasonal changes.
The author shares a curated list of five recommended science books, emphasizing that they are well-reviewed and written by experts in their fields. The selection includes titles from prominent scientists including Neil Degrasse Tyson and David Deutsch, targeting a general audience interested in science.
Updated March 2026 The ashen light is a faint glow, which many people claim to have seen on the night side of Venus. The Italian astronomer Giovanni Riccioli (1598 -1671) first reported it back in 1643, 33 years after Galileo had made the first observations of Venus with a telescope and discovered the planet had… Continue reading The Mystery of the Ashen Light of Venus
Updated 30 November 2025 A lot has happened since I wrote a post back in June 2025 about the Artemis programme. At the time it looked like America would be landing astronauts on the Moon in mid-2027. However in October, concerned by delays in SpaceX’s Starship HLS, the NASA Acting Administrator Sean Duffy revealed that… Continue reading NASA’s Artemis Moon Missions Update
Explaining Science 