Astronomy Items
Revised and updated 12 February 2026 July 25, is one of the four days a year in which the length of the apparent solar day, the natural day measured by the rising and setting of the Sun, is 24 hours. I have written about this in previous posts but I thought it be worth mentioning… Continue reading Understanding Solar Day Length Variation
Back in 2019, the year before the pandemic, many of you will have seen images of long ‘trains’ composed of up to sixty SpaceX Starlink satellites crossing the sky in a straight line. These pictures hit the headlines not only because of the number of satellites, but because of their brightness. A 'train' of… Continue reading Starlink and other Large Satellite Constellations
Updated Marck 2026 As most people with an interest in astronomy know, Sirius is the brightest star in the night sky. On the magnitude scale used by astronomers it has a magnitude of -1.46, easily outshining all other stars. The apparent brightness of a star depends on two factors: how luminous it is (its intrinsic… Continue reading Sirius: The Dog Star and Its History
Doesn't time fly ! 🙂 Ten years have passed since I wrote my first post on my Explaining Science blog (originally called The Science Geek). I have decided to mark the occasion by reblogging my first ever post. Over the last ten years the question whether there are primitive life forms on Saturn’s icy moon… Continue reading Enceladus Could there be life 10 years on
This year, the northern hemisphere winter solstice will fall on 22 December. On this date there are the fewest hours of daylight and, during the day, the Sun reaches its lowest elevation. The origin of the word solstice is from two Latin words: sol, which means Sun, and sistere, to stand still. At the time of the winter… Continue reading December 22 2023 – the solstice
Explaining Science 