These are some of my cosmology posts
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Lunar eclipse 27 July 2018
On 27 July 2018 there will be a total eclipse of the Moon, which will be viewable from many areas of the world. This will be the first total lunar eclipse able to be observed in the UK for nearly three years and it will be worth making the effort to see, especially since, for…
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Methane on Mars
I was very excited to read about the discovery published last week by NASA’s Curiosity rover of the seasonal variation in the amount of methane in Mars’ atmosphere. Curiosity found that the average methane concentration varied from 0.24 parts per billion (ppb) in the northern hemisphere winter to around 0.65 ppb in the summer. This…
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June 21 2018 – the solstice
This year, the June solstice will fall on 21 June. In the northern hemisphere, it is the day when there is the most daylight and when the Sun is at its highest in the midday sky. Sunrise at the solstice at Stonehenge, England – image from Wikimedia commons The origin of the word solstice is…
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The anthropic principle.
The post discusses the anthropic principle, which suggests that the laws of physics and the universe are finely tuned for life. Introduced by Brandon Carter in 1973, it highlights how slight changes in fundamental forces would prevent life. The article contrasts strong and weak anthropic principles and touches upon concepts like the Omega Point and…
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Jupiter at opposition 9 May 2018
On May 9 Jupiter is at opposition. This event, which occurs every 399 days, happens when Jupiter is at its closest to the Earth and at its brightest. To the naked eye it is a brilliant white object, three times brighter than the brightest star. Features such as coloured bands and the famous great red…
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The Rare Earth hypothesis
Updated 15 December 2025 Ever since the pioneering work of Frank Drake (1930-2022) way back in 1960, astronomers have been looking for radio signals from extraterrestrial civilisations but all SETI searches have failed to find anything. This could be because Earth-like planets containing complex life forms (such as ourselves) are rare in the Universe and only…
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Galileo and the telescope
Revised 21 November 2025 Telescopes are instruments which use multiple lenses to produce magnified images of distant objects. It is unclear who invented the first telescope: lenses had been widely used in Europe to correct poor eyesight since the fourteenth century and I expect that, over time, the telescope was actually invented many times by…
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20 March 2018 – the equinox
Now that we are in the month of March, it is only a short time until 21 March, the first day of spring (or first day of autumn if you’re one of my readers in the southern hemisphere). There is a commonly held view that 21 March is an equinox and that the equinoxes are the two…
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American manned spaceflight in 2018?
This post has been superseded by the later post American spaceflight in 2019 As readers of a previous post will know, since the retirement of the Space Shuttle in July 2011, America has been unable to put any astronauts into orbit around the Earth. Instead, it has been reliant on the Russian Soyuz spacecraft to…
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Kepler’s other achievements
As discussed in my previous post, Kepler’s improvement of Copernicus’s heliocentric system led to its more general acceptance, and his three laws describing the way planets move are fundamental laws of astronomy. However, this wasn’t his only contribution to science. He was one of the greatest thinkers of the seventeenth century scientific revolution and in…
Explaining Science 