Astronomy Items
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, spacecraft powered by… Continue reading Solar Sails: Fuel-Free Space Travel
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… Continue reading How we can see some of the Moon’s far side
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… Continue reading Lunar Stationary Orbits: Why They are Impossible
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).… Continue reading The Perseids Meteor Shower 2025
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.
Explaining Science 