These are some of my latest posts
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Solar Sails
Update 21 September 2025 As this is a changing area, I have replaced this post from 2021 with a revised and updated one. This is available at https://explainingscience.org/2025/09/21/solar-sails-fuel-free-space-travel/ I have also created a video which goes into solar sails in much more detail
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Human spaceflight in 2021
2021 will be an interesting year for human space flight. Not only is it the sixtieth anniversary of Yuri Gagarin’s historic first manned spaceflight, but it will be the first time that a privately operated spacecraft will arrive at the International Space Station (ISS). This private spacecraft is not just a one-off but will be…
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Chinese Moon samples
Like many of my readers I was pleased to see that the Chang’e 5 spacecraft returned to Earth on 16 December 2020 with around 2 kg of lunar rocks. This great achievement was the first lunar sample return mission for China and is indeed the first time any rocks have been brought from the Moon…
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Dark energy an unexpected finding
I offered recently to write an article for my local astronomy society on the discovery of dark energy. It is an expanded version of the blog post I wrote on the topic last year and, at over 3000 words, it is longer than my usual posts. I thought it would be of interest to many…
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Arecibo Update
Since the publication of this post on 2 December 2020 it appears that Arecibo observatory may be rebuilt. Although the $8 million pledged by the Puerto Rico Rico government is clearly not enough https://www.engadget.com/puerto-rico-approves-8-million-to-rebuild-arecibo-telescope-155454170.html I was saddened to see that the Arecibo Observatory in Puerto Rico has closed following catastrophic damage to its cables and…
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Why Haven’t We Heard from Aliens?
Interest in the Search for Extra-Terrestrial Intelligence (SETI) has risen, highlighted by the Allen Telescope Array. Despite decades of searching for alien signals, no evidence has been found, which may be due to the rarity of intelligent life, communication methods, or missed signals. Some theories suggest advanced civilizations may self-destruct or remain undetected.… Continue reading…
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The changing pole star
Polaris, commonly known as the pole star, is situated near the North Celestial Pole and has been used for centuries for navigation. But Polaris hasn’t always been the Pole Star and won’t be in future. This is gradually changing over a 25 800 year cycle.… Continue reading The changing pole star →
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Life on Venus?
Many of you will have seen the story widely reported in the media of the discovery of the gas phosphine in the clouds of Venus – if not, you can find the story here: https://www.bbc.co.uk/news/science-environment-54133538. On Earth phosphine is produced by bacteria and it has led to the interesting speculation as to whether there could be…
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Surveying the Cosmos – Part II
In a previous post I talked about the Large Synoptic Survey Telescope (LSST), a large telescope being built in Chile which will spend 90% of its time surveying most of the sky a total of 1000 times over a 10 year period (in the remaining 10% it will revisit areas of specific interest). In this…
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11-12 August 2020 – the Perseids
For revised post containing more tips on how to view the Perseids see The Perseids 2021. 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 a very high speed (in the case of the Perseids around 200,000 km/h). As…
Explaining Science 