The Sky Above You, August 2025
by Duncan Lunan
The Moon is Full on August 9th, and it will be New on August 23rd. It passes Saturn on the 11th and 12th, Venus and Jupiter on the 20th and 21st, and Mars on the 26th. On the 17th the Moon is near the Pleiades and Aldebaran in Taurus, an early sign of Autumn.
After inferior conjunction with the Sun on 1st August, the planet Mercury reappears below and to the left of Venus in the second half of August, rising at 4.15 a.m., at greatest elongation from the Sun on August 19th. The Moon is above Mercury on the morning of the 21st.
Venus in Gemini passes less than a degree from Jupiter on the morning of the 12th, rising about 2.30 a.m. and easily seen together in binoculars, well worth looking for with or without them, and Venus then becomes lower in the sky as the month goes on. The thin crescent Moon will be left of them on the 20th and 21st. By the end of August Venus will be 10 degrees east of Jupiter and 2 degrees from the Beehive Cluster in Cancer.
In the July 2025 'Sky Above You' (ON, 1st July 2025), I described how the Earth was hit by a very powerful Coronal Mass Ejection from the Sun in 12,350 BC during a longer drop in the intensity of Earth's magnetic field. Yet it was reckoned that before and after it the rate of carbon-14 formation in the atmosphere was down due to reduced penetration by cosmic rays, which would suggest that the Sun was more active than usual. Major CME events ('Carrington events') aren't particularly associated with heightened solar activity: the known examples of the last 12,000 years were in 7176 BC, 5259 BC, 663 BC and 775 AD, when the Sun was active, but not unusually so.
What is clear is a correlation of heightened activity in the last 3000 years with periods of warmer climate such as the 'Roman warming' and the 'mediaeval warming', when temperatures were generally higher than today's, e.g. both times viniculture was widespread in the British Isles, up into Scotland, and lower activity correlates with colder weather and severe winters, e.g. ice fairs on the Thames. (John A. Eddy, 'The Maunder Minimum', Science, (18th June, 1976), and 'The Case of the Missing Sunspots', Scientific American, May 1977; for specific examples, Adrian Berry, 'Arctic Search for a Race that Vanished', Daily Telegraph, 3rd May, 1982; 'Naked Planet: Grand Canyon', Channel 4, 4th October 1999. (I'm putting stress on this because a reader of my 'Politics of Survival, Part 1', ON, 16th February 2025, claimed that it was 'ill-informed', 'embarrassing and shameful' even to mention it.)
Until recently the difficulty with that correlation was the lack of a mechanism to explain it. Heightened solar activity would be marked by increases in sunspots, but even naked-eye ones wouldn't make a difference to incoming solar heating at this distance. But a possible explanation was provided as Voyagers 1 and 2 passed through the heliopause, at the boundary of the Solar Wind, in 2013 and 2020. Both spacecraft passed through the boundary several times, as the heliosphere expanded and contracted, responding to changes in outflow from the Sun, observed a few days earlier by Sun-watching spacecraft such as SOHO at the Sun-Earth L1 point, and accompanied by drops of 90% in the counts of cosmic rays. It has been suggested that the correlation of global warming and cooling with solar activity over the last 5000 years may be due to fluctuations in the input of lower-energy galactic cosmic rays, which, it's further suggested, may trigger the formation of raindrops (literally, by 'cloud chamber' effects), leading to increased precipitation worldwide. If so, one would expect increased cloud formation and lower temperatures when the magnetic field was lower in strength - unless the Sun was more active at the time. The 12,350 BC event was in the Late Glacial when the northern hemisphere was warming, suggesting clearer skies, but if the Sun was unusually active then, it might explain a lower cosmic ray count nevertheless; but there was a very high peak of glaciation in Greenland just about then, presumably caused by higher rainfall.
As translators sometimes point out (e.g. in working from Polish to English, or English to Italian), one source of confusion can be that English not only uses words in different ways without changes of inflection, but often uses the same word without change for different meanings. The translator of Ice, by Jacek Dukaj, which I've just reviewed for ParSec and will be published in English for the first time in November, points out that English has many meanings for the word 'icy', where Polish has a separate word for each; and I had to give a new Italian editor of Sydney Jordan's work a lot of help with compound nouns like 'strike command' (order somebody to hit someone?) or 'command loop' (worn round the neck to indicate rank?) My favourite question was 'What's a laser Morse?', which sorely tempted me to reply, 'I thought you would have known that, Lewis'. In science and in common speech, words can even be frozen when their original meaning is proven wrong - 'tidal wave' is an example, when it's long been known that they're caused by earthquakes, volcanoes and impacts, and have no connection with tides. The Japanese tsunami, 'harbour wave', is not much better because it describes only a local effect. Nothing beats the endless confusion between rays, radiation and radioactivity, which would take too long to explain here. But for the record, 'cosmic rays' in the paragraph above are so called because they were first thought to be electromagnetic radiation, until it was shown that they were influenced by the Earth's magnetic field and had to be charged particles. These days the term is correctly used for atomic nuclei - lighter ones from the Sun, highest-energy, most massive ones from neutron stars, supernovae and regions of star formation. The ones discussed above are lower-energy interstellar ones, most of them stopped at the heliopause. They are not to be confused with solar cosmic rays, nor with solar ultraviolet radiation, which is electromagnetic and near the blue end of the visual spectrum. Bees use it for navigation, but human skin needs protection from it, either by melanin produced naturally, or by sunscreen and clothing. Now read on...
In April it was suggested that in the 41,000 BC 'Laschamp Event', a magnetic polar excursion when the magnetic field was weakened overall, might have led to the extinction of the Neanderthals under a thinner ozone layer, hence more ultraviolet radiation, while changes in our behaviour protected us from some of the worst effects. (University of Michigan, 'Earth's magnetic pole shift: Sunscreen, clothes and caves may have helped Homo sapiens survive 41,000 years ago', Phys.Org, April 16th, 2025.) If the cosmic ray penetration hypothesis is correct, in a weakened magnetic field penetration should have been higher, likewise rainfall, so temperatures should have shown a downturn and clouds would provide more protection. My first thought was that the adoption of stitched clothing and living in caves might have had more to do with rain and cold than to sunburn, and the increased wearing of ochre might simply be for decoration rather than protective. But while there was a small peak in Greenland glaciation then, it's not a dramatically high one like the one c.12,350. So maybe the Sun's activity was nearer normal and increased solar u-v really was a problem, right enough.
Mars in Virgo sets at 10.30 p.m., with possibly a chance to glimpse it after sunset, before disappearing behind the Sun till next year. Mars is passed by the young crescent Moon on the 26th.
Jupiter in Gemini is still bright in the morning sky, near Venus and the Moon as above, and will become visible for more of the night as Autumn and Winter draw on.
Saturn in Pisces rises about 9.30 p.m., with Neptune a degree to the north on the 5th and 6th, and the Moon will be near Saturn on the 11th and 12th. The August issue of Astronomy Now has a table of events involving the moons Rhea and Titan during the month.
On 5th July a video taken by Mario Rana of the DeTeCt programme, studying images of Saturn, showed a bright spot lasting a few seconds, near the rim of the planet. If confirmed, and if it was an impact, it may have been an object up to a kilometre across, something which might be expected every 3000 years or so. (Vishwam Sankaran, 'Astronomers call for help identifying mystery object that may have just crashed into Saturn', MSN, online, 6th July 2025). If so, by comparison with the Shoemaker-Levy impacts on Jupiter in 1994, we might expect to see a visible impact feature as the planet rotates, and maybe images showing the impactor beforehand, though at that distance from the Sun there may not be a tail to make it prominent.
Uranus rises at 11.30 p.m., 4 degrees below the Pleiades in Taurus, and is 5 degress south of the Moon on August 16th.
Neptune in Pisces rises at 9.30 p.m., still not far from Saturn and closest on the 6th.
The Perseid meteors from Comet Swift-Tuttle, first of the major meteor showers in the latter part of the year, come to a peak on the night of the 12th to 13th August, but will be diminished this year by bright moonlight right from when it gets dark. The lesser Aurigid shower peaks with about 10 meteors per hour on the 31st, but as the Moon will be at Third Quarter little can be expected then either.
In 'Let's Talk about the Neighbours' (ON, 22nd June 2025), in discussing features around our Milky Way galaxy, I pointed out that in cosmology the word 'local' can apply to enormous differences in scale, from the 'local bubble' 500 light-years in radius, formed by supernova shockwaves, to the 'local' void encompassed by the Ho'oleilana Baryon Acoustic Oscillation bubble, 820 million light-years distant and 1 billion light-years across. Such features are literal echoes of the Big Bang, formed by sound-waves in the very early Universe and inflated to huge size in its expansion. News articles have suggested that if we are located near the centre of one, the concentration of matter around its perimeter could explain the different values for the expansion (the Hubble Constant) which are obtained from the redshifts of more distance objects (The Hubble Tension, currently a major mystery in cosmology). See for example EarthSky Voices, 'Earth could be in a void, Big Bang sound waves suggest', EarthSky, online, July 8th, 2025. It sounds plausible, but the puzzle is that the illustrations I used in 'Let's Talk about the Neighbours' clearly show our Local Group of galaxies near the perimeter but outside a Local Void of that size. The matter was to be aired in a discussion in the National Astronomy Meeting on July 9th, and it will be interesting to hear more.
Duncan Lunan’s recent books are available through Amazon; details are on Duncan’s website, www.duncanlunan.com.
The Sky Above You
By Duncan Lunan
About this Column
I began writing this column in early 1983 at the suggestion of the late Chris Boyce. At that time the Post Office would allow 1000 free mailings to start a new business, just under the number of small press newspapers in the UK at the time. I printed a flyer with the help of John Braithwaite (of Braithwaite Telescopes) offering a three-part column for £5, with the sky this month, a series of articles for beginners, and a monthly news feature. The column ran from May 1983 to May 1993 in various newspapers and magazines, but never in more than five outlets at a time, although every one of those 1000-plus papers would have included an astrology column. Since then it’s appeared sporadically in a range of publications including The Southsider in Glasgow and the Dalyan Courier in Turkey, but most often, normally three times per year, in Jeff Hawke’s Cosmos from the first issue in March 2003 until the last in January 2018, with a last piece in “Jeff Hawke, The Epilogue” (Jeff Hawke Club, 2020). It continues to appear monthly in Troon's Going Out and Orkney News, with an expanded version broadcast monthly on Arransound Radio since August 2023
The monthly maps for the column were drawn for me by Jim Barker, based on similar, uncredited ones in Dr. Leon Hausman’s “Astronomy Handbook” (Fawcett Publications, 1956). Jim had to redraw or elongate several of them because they were drawn for mid-US latitudes, about 40 degrees North, making them usable over most of the northern hemisphere. The biggest change needed was in November when only Dubhe, Merak and Megrez of the Big Dipper, as the US version called it, were visible at that latitude. In the UK, all the stars of the Plough are circumpolar, always above the horizon. We decided to keep an insert in the January map showing the position of M42, the Great Nebula in the Sword of Orion, and for that reason, to stick with the set time of 9 p.m., (10 p.m. BST in summer), although in Scotland the sky isn’t dark then during June and July.
To use the maps in theory you should hold them overhead, aligning the North edge to true north, marked by Polaris and indicated by Dubhe and Merak, the Pointers. It’s more practical to hold the map in front of you when looking south and then rotate it as you face east, south and west. Some readers are confused because east is on the left, opposite to terrestrial maps, but that’s because they’re the other way up. When you’re facing south and looking at the sky, east is on your left.
The star patterns are the same for each month of each year, and only the positions of the planets change. (“Astronomy Handbook” accidentally shows Saturn in Virgo during May, showing that the maps weren’t originally drawn for the Hausman book.) Consequently regular readers for a year will by then have built up a complete set of twelve.
©DuncanLunan2013, updated monthly since then.