The Sky Above You, July 2025
by Duncan Lunan
The Moon is Full on July 10th, and it will be New on July 24th. It passes Saturn on the 15th, Venus on the 21st and 22nd, Jupiter on the 23rd and Mars on the 28th. There are no planets visible in the evening sky unless you count Mars, which will be setting as it gets dark in Scotland.
It has been confirmed that the crash of the Japanese lunar lander Resilience In Mare Frigoris on 5th June was due to a failure of the laser altimeter, in the final stage of approach. There are four possible causes, including an anomalous return from the lunar surface, and all are under investigation. The July issue of Astronomy Now has a 2-page article on Mare Frigoris, 'Warm to the Sea of Cold', starting with the crater Harpalus, modelled in detail by Chesley Bonestell for the US spaceship landing in the 1950 film Destination Moon, and afterwards featured in Cornelius Ryan, ed., Man on the Moon (Sidgwick & Jackson, 1952).
In June the European Space Agency released the first images of the south pole of the Sun, obtained by the Solar Orbiter probe as it continues to increase its elevation above the solar equator, in repeated flybys of the planet Venus. It's now at an elevation of 17 degrees, and will change up to 24 degrees in December 2025 and 33 degrees in June 2029. The magnetic map of the polar region shows areas of north and south polarity, suggesting that the Sun's magnetic field is about to flip, as it does every 11 years in conjunction with the sunspot cycle, which is now approaching maximum activity. These are the first direct studies of the solar poles since the International Solar Probe Mission of 1990, which was to have consisted of two probes launched simultaneously, to go over the poles of Jupiter and then the Sun's. The US contribution was cancelled, causing such disappointment that Margaret Thatcher was moved to protest, to no avail. But the ESA ISPM 'Ulysses', in which Britain had a major part, did not carry cameras because it was felt that the results wouldn't justify doing so, which may now turn out to be wrong. Solar Orbiter has been excluded from the list of missions NASA is being forced to cut, which is nice of them of since it's not their spacecraft, but presumably it means that what's left of the Solar Physics Division will still be allowed to look on. The same applies to SOHO, which has been operational since 1995 after a remarkable long-distance rescue by ESA technicians in 1998, and to PUNCH, the recently launched US solar observer, which returned its first coronagraph film of a solar outburst on June 3rd. Its resolution is higher than SOHO's, which frequently captures Sun-grazing comets and planets in conjunction with the Sun (see 'The Sky Above You, May 2025', Orkney News, 1st May 2025), but the PUNCH film shows the constellation Orion behind the Sun, including the four principal stars, the three stars of the Belt and even the Great Nebula in the Sword (C. Alex Young, Raúl Cortés and Armando Caussade, 'Sun news: First eruption imagery from PUNCH mission!', EarthSky, online, 12th June 2025.)
In the version of this column on Orkney News you can find illustrated versions of all these stories and also of last month's one about Coronal Mass Ejections and the threat they pose to civilisation on Earth.
The planet Mercury is invisible near the Sun in July, though at greatest elongation from it on July 4th, and reaches inferior conjunction on this side of the Sun on August 1st.
Venus in Aries rises at 2 a.m., very bright in the morning sky, in line with Uranus and the Pleiades on the 4th, passed by the Moon on the 21st and 22nd.
Mars is low in Leo, moving into Virgo on the 28th, setting about 11 p.m. when the sky is barely dark here. The Moon is near Mars on July 28th, though hard to see by then.
Although the Perseverance lander went to Jezero crater in search of sedimentary rocks, and did find them in the delta of the river which broke through the crater wall long ago, surprisingly it has also found volcanic rocks, not only on the crater floor but also on the river floor (possibly washed downstream), but also on the rim, suggesting possible ejection from a volcano somewhere in the vicinity. On December 10th 2024 it reached Lookout Hill, on the inner rim (see 'The Sky Above You, January 2025, ON, 1st January 2025). From there it saw terrain outside the crater for the first time, revealing a volcanic hill in the middle distance, and beyond it two near identical peaks which can be seen from orbit, on either side of a long chasm which is obviously younger than they are, possibly formed by the impact. When I wrote these up in January, I could only find them in YouTube videos ('Mars Guy', 'Perseverance Tops Out and Looks Beyond', December 15th, 2024), and frustratingly that's still the case. The only still image I can find is looking west, towards the crater rim, and the only map doesn't show them either.
But now a much larger feature on the southwest of the rim, previously designated Jezero Mons, has been identified as a volcano 13 miles across, nearly half the size of Jezero crater itself. How old it is has still to be determined, but it looks as if it was active after the crater formed, if not before. That it has remained 'hidden in plain sight' all this time suggests to me that it may have been mostly buried by the impact. Commentators have remarked on the similarity to the huge extinct volcano in Noctis Labyrinthis, undiscovered since the feature was photographed by Mariner 9 in 1971, which I wrote up in 'The Sky Above You, April 2024' (ON, 3rd April 2024), but this one is on the crater rim, whereas the Noctis one has largely been destroyed by water action - much as the outer layers of Ailsa Craig have been washed away, leaving only the central granite plug. On hearing that, my sister remarked, "They must have used a very strong detergent".
By mid-month Jupiter rises about 3.30 a.m., in Gemini, below and left of Venus, near the waning crescent Moon on the 23rd, still very low ('barely up from Scotland', according to Astronomy Now).
Saturn in Pisces rises about 1.30 a.m., within a degree of Neptune all month. As the Earth catches up with Saturn in their orbits, Saturn is 'stationary' on July 14th, and the Moon will be near Saturn on the 15th. In 'The Sky Above You' for May (ON, 1st May 2025), I quoted Nigel Henbest, in Stargazing 2025, saying that Saturn should look markedly different when now we're observing the rings from the other side, from below instead of above. This has now been proved true in a photograph by Robert Lunsford of California on May 31, 2025, showing the shadowed side of the rings, with Titan’s shadow on the northern hemisphere of Saturn, and Titan itself at the 10 o’clock position. Titan is almost the largest moon in the Solar System, second only to Jupiter's Ganymede, and it's the only moon with a dense atmosphere. Normally it's easily seen with even a small telescope (it was prominent in the 3-inch refractor which I had from 1967 till the early 80s), but it's not so easy to see when the Saturn system is edge-on to us, as at present, and due to low contrast it's particularly hard to see crossing the planet, which happens only every 15 years. Its shadow is much more prominent, and shadow transits will continue until October - a full list of them can be found in Bob King, 'Titan Shadow Transit Season Underway', Sky & Telescope online, May 14th 2025. The moon itself will continue to transit the planet every 16 days until January 25th - no doubt Burns would approve. Meanwhile, for those with larger telescopes, transits and shadow transits of the smaller moons Rhea and Dione will occur in July and August (Anon, 'Saturn in the Small Hours', Astronomy Now, July 2025).
Uranus rises at 1.30 a.m., below the Pleiades in Taurus, within binocular field of view, and will be between them and Venus on the 4th, passed by the Moon on the 21st and 22nd. New discoveries announced last year brought the total numbers of Uranus moons to 28, and 16 for Neptune (Paul Scott Anderson, 'New Moons! Uranus Now Has 28 and Neptune 16', EarthSky, online, 27th February 2024). All the large moons of Uranus have trapped rotations, keeping the same faces always towards the planet, and with growing interest in them leading to a run of new discoveries, the latest is that the outer two large moons, Titania and Oberon, both have leading hemispheres which are darker than the other, while Ariel and Umbriel have no marked shading, and Miranda is just plain weird. (Paul Scott Anderson, '2 of Uranus’ largest moons have surprising dark sides', EarthSky, June 19th 2025.) The planet's magnetic field is inclined at 59 degrees to the plane of the equator and the orbits of the moons, so it was thought that the trailing hemispheres would be hit by more particles captured from the solar wind. Dust sputtered off from the smaller moons seems a more likely explanation, and Titania and Oberon might be shielding the next two inward, but the problem I have is that the dust flow should be coming from outside the orbit of Oberon, and all the small moons are further in, embedded among the rings. There might be another moon still further out, like Phoebe, the captured 'Centaur' from the Kuiper Belt which is orbiting Saturn, and perhaps like Phoebe it might be in retrograde orbit and emitting dust into a very large outer ring, but I've yet to see any of that suggested.
Neptune in Pisces rises at 11.30 p.m., just one degree away from Saturn all month, closest to it and above it on the 6th. Neptune reaches its 'stationary point' on the 5th, as the Earth begins to overtake it, and is passed by the Moon on the 16th.
For months now I've been plugging the possibility of a nova (stellar explosion) in the constellation Corona Borealis, which is actually 'due' next year, if it sticks to a possible 80-year periodicity, but last year the star dimmed as it did before the previous outburst. At nearly 80 I've never seen a nova, so I've kept watch on winter mornings and spring evenings. The constellation isn't visible in Scottish summer till the small hours, so for the last couple of months I've been watching the news to see if I should get up for it - and there have been no updates because nothing has happened yet. Now there is a nova, above Delta and Beta Lupi (Fig. 33), in the constellation Lupus, the Wolf, in the southern hemisphere, between the 'sting' of Scorpius which we can't see from here and the constellation Centaurus, which includes the Guardians of the Cross, the top of which is visible at bottom right of the map. Frustrating for Scottish observers, but that's astronomy for you.
There's the chance to see high-level noctilucent clouds in July, lit from below the horizon in the north around midnight. NLC was captured by Harlan Thomas in Alberta on June 9th, with aurora, and not for the first time - he had previously done it in 2020, with Comet NEOWISE for good measure.
There are two meteor showers peaking on July 30th, but they are the Alpha-Capricornids and the Delta-Aquarids. Both constellations are too far south to be readily visible from Scotland, but if you do see any meteors coming up from the south that night, they're liable to be from one shower or the other.
Stop Press. The July 'Space Notes' (ON, 29th June 2025), contain a report on an event last year at the Australian Square Kilometre Array Pathfinder radiotelescopes at Murchison in Western Australia. In intensity the pulse received resembled a Fast Radio Burst, one of the little-understood phenomena coming from galaxies in the Cosmic Web (see 'Let's Talk About the Neighbours', ON, 22nd June 2025). Just as the article was accepted, a first-hand account by Clancey William James was published in Nature Briefing online (27th June), reproduced from The Conversation the same day ('A strange bright burst in space baffled astronomers for more than a year. Now, they’ve solved the mystery'), explaining the reasoning that was used to identify the source, which has taken a year. Though like an FRB event, the June 13th 2024 burst took nanoseconds rather than milliseconds, 10,000 times shorter, and it didn't show the dispersion in time between high and lower frequencies which is caused by FRBs passing through intergalactic gas, only recently discovered and featured in 'Let's Talk About the Neighbours'. One of the objectives of the SKA is to pinpoint the sources of FRBs rapidly, so that other instruments can be turned on them before traces fade. In this case, the burst was so short that it could only be pinpointed by subtracting the data from outlying dishes of the array, analogous to the subtraction technique used to detect a possible planet of Alpha Centauri (see 'Space Notes, June 2025', ON, 1st June 2025). Even so, when spotted, the source showed blurring which could only be caused by orbital motion around the Earth, indicating a height of 4,500 km (2800 miles). And that identified it as the defunct satellite Relay 2, used in communications experiments in 1964-65. As it couldn't have generated the signal even when it was working, the most likely cause is an electrostatic discharge, possibly caused by a plasma cloud from the Sun (though the Sun was quiet at the time), or a micrometeoroid impact - both unlikely, but the only explanations going at the moment. The artist David A. Hardy has a series of magazine covers for Fantasy & Science Fiction showing a 'benevolent gremlin' called Bhem playing tricks with Voyager 2, the Apollo 15 landing site, the Hubble telescope and an Intelsat 4 comsat, so pdrhaps he's back in business!
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.