These are some of my cosmology posts
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The Mystery of the Ashen Light of Venus
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…
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NASA’s Artemis Moon Missions Update
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…
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The Clocks go Back 26 October 2025
Updated March 2026 At 0100 UTC (2 AM local time) on Sunday 26 October, the UK like most of Europe will put it clocks back by one hour as is comes to an end of Daylight Saving Time. Most of the USA will follow a week later. In this post I’ll give an overview of…
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Solar Sails: Fuel-Free Space Travel
Updated August 2026 Solar sails are the only method of spacecraft propulsion in which no fuel is needed. Until recently spacecraft powered by solar sails were the stuff of science fiction. However, following the success of the Japanese spacecraft IKAROS in 2010 the crowd-funded Light Sail 2 spacecraft in 2019 and NASA’s ACS3 in 2024,…
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How we can see some of the Moon’s far side
Lunar libration is a ‘wobble’ caused mainly by the Moon’s elliptical orbit and axial tilt. It allows us to see about 59% of the Moon’s surface over time, effectively revealing 18% of the ‘far side’ that would otherwise be hidden. This post discusses this interesting phenomenon. Updated 7 January 2026 Many people think that the…
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Lunar Stationary Orbits: Why They are Impossible
Updated April 2026 – A friend of mine recently asked me whether it was possible to have a lunar-stationary orbit. This would be the equivalent of a geostationary orbit, but around the Moon rather than the Earth. To an observer on the Moon, a lunar-stationary satellite would appear fixed in the sky and if…
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Latitude and Longitude on the Moon and the Planets
This post discusses the use of latitude and longitude for mapping locations on the Moon and other celestial bodies in the Solar System. It explains how these coordinates are defined, the arbitrary selection of prime meridians, and variations across different planets, emphasizing the importance of consistent astronomical conventions for navigation and mapping.… Continue reading Latitude…
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The Perseids Meteor Shower 2025
The night of 12/13 August will be the peak of the Perseids, one of the most famous prolific meteor showers. Meteors (also known as shooting stars) are bright streaks of light caused by small lumps of rock or metal called meteoroids hitting the Earth’s atmosphere at very high speed (in the case of the Perseids around 200,000 km/h).…
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Twilight and the Long Summer Evenings
There are extended daylight hours and twilight periods during summer at northern latitudes The article focusses on Manchester and Shetland. It defines twilight and its three stages, highlights the Sun’s path at various times of the year, and explains the phenomenon of “Simmer Dim” in Shetland and the celebrations associated with these light nights.… Continue…
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NASA’s Artemis Moon Missions
In March 2019 the American Vice President Mike Pence surprised many people when he announced an extremely ambitious plan to put American astronauts on the Moon in 2024. NASA named its new crewed Moon programme Artemis, after Apollo’s sister in Greek mythology. Perhaps unsurprisingly, the dates have slipped since this extremely ambitious announcement. After numerous…
Explaining Science 