Updated 16 December 2025 As discussed in my earlier post on Dark Skies , light pollution is a major nuisance to astronomers both amateur and professional. When astronomers classify how much light pollution there is at a particular location, they often use the Bortle Scale, devised by John Bortle and first published in the popular astronomy… Continue reading Measuring and Mapping Light Pollution
Tag: Astronomy
Astronomy Items
SpaceX Starlink Satellites (2020)
Update 16 March 2022- click on the image below to view a video of much of the information in this post https://youtu.be/smCG4mWKjPA Many of you will have seenthe pictures in 2019 showing long ‘trains’ composed of as many as sixty SpaceX Starlink satellites crossing the sky. A 'train' of SpaceX Starlink satellites just after… Continue reading SpaceX Starlink Satellites (2020)
e-book on Venus and how to Terraform it
Updated 7 December 2025 I have extensively expanded and rewritten all three “A Short Guide to…” e-books. These books available on Kindle for a competitive price I hope you enjoy reading the new versions of these books (if you’ve not done so already). Venus is, the planet closest to the Earth in size and internal… Continue reading e-book on Venus and how to Terraform it
The evenings are drawing out already
Updated 13 December 2025 ------------------------------ As I complete this post, it's completely dark outside and it's only 5 o'clock in the afternoon; most people I come across think that it will continue to get dark earlier and earlier in the afternoons until the date of the winter solstice which for the UK in 2025 falls… Continue reading The evenings are drawing out already
The discovery of dark energy
The is a now an expanded and updated version of this post available at: https://explainingscience.org/2020/12/10/dark-energy-an-unexpected-finding/ The Expansion of the Universe Astronomers have known since the late 1920’s that the Universe is expanding. By this we mean that distances between objects which are not bound together by another force, such as gravity, increase over time.… Continue reading The discovery of dark energy
Explaining Science 