Listen: https://soundcloud.com/astrophiz/astrophiz-ep237-july-sky-guide-ian-musgrave
Full Transcript below
Celebrate a decade of stargazing with Astrophiz! In this very special milestone episode, host Brendan O’Brien sits down with acclaimed scientist, educator, and avid amateur astronomer Dr. Ian Musgrave to celebrate 10 years of fabulous Astrophiz Sky Guides and the 19th anniversary of his renowned Astroblog.
Packed with essential observational astronomy tips for the southern hemisphere, Ian delivers your comprehensive July Sky Guide. Discover when and where to spot the planet dance as it transfers to the morning skies, featuring a spectacular close encounter between Mars and Uranus in Taurus, and find out how to track Saturn as it begins its retrograde path toward September opposition.
Plus, get the best viewing times for the Southern Delta Aquariid meteor shower (despite a competing full moon!) and learn how to navigate the winter Milky Way to find stunning deep-sky treasures like Omega Centauri, the Carina Nebula, and Ptolemy’s Cluster.
In a deeply moving Tangent, Ian dedicates this anniversary edition to the memory of his late son, Jack. Shifting his gaze from the stars to the atmosphere, Ian tackles the historical beauty, science, and nomenclature of cloud formations—from Luke Howard’s classic classifications to the newly recognized Asperitas clouds—while playfully dismantling modern “cloud-shaming” conspiracies.
Whether you are a seasoned astrophotographer or an amateur backyard astronomer, grab your binoculars, set your calendars, and remember to keep looking up!
In This Episode:
**** Looking Ahead: Future transits, solar eclipses, and Episode 238 ‘Rosetta Stone in the Sky’ teaser.
**** Celebrating 10 Years of Astrophiz Sky Guides & 19 Years of Astroblog.
**** July Moon Phases, Solstice, and Earth at Aphelion.
**** Evening Skies: Saying goodbye to Jupiter; Venus climbs through Leo.
**** Morning Skies: The Mars-Uranus conjunction and Saturn’s retrograde track.
**** Deep-Sky Astronomy: Scanning Scorpius, Sagittarius, and the Southern Cross.
**** Southern Delta Aquariids Meteor Shower Peak & Viewing Advice.
**** The Tangent: A tribute to Jack, the beauty of clouds, and Luke Howard’s nomenclature.
Full Transcript:
Introduction
Brendan: Welcome to episode 237 of Astrophiz and our 10-year anniversary of Ian’s fabulous SkyGuides. My name is Brendan O’Brien and Astrophiz is produced on Yorta Yorta, Pangarang and Kaurna Country.
We celebrate the first astronomers of this land.
Monthly, we explore the universe with the world’s leading scientists. For transcripts and more, visit astrophizDOTcom. And here is Dr. Ian Musgrave with your July Sky Guide.
Brendan: Hello Ian.
Ian: Hello Brendan.
Brendan: … And hello listeners…. Dr. Ian Musgrave is a nationally awarded scientist and educator based at the University of Adelaide, and he’s uniquely recognised for his expertise spanning both the microscopic world of pharmacology and toxicology and the macroscopic world of astronomy. Beyond his laboratory research, Ian is a highly active and passionate science communicator. He was named the unsung hero of science communication, is a strong advocate for evidence-based science, has received the Thornet Award for the promotion of reason, and is widely known in the community as an avid amateur astronomer. He seamlessly blends his scientific precision with his passion for the night sky.
Now, Ian started his Astroblog in June 2007.
So, Ian .., as well as celebrating your 10 years at Astrophiz producing your sky guides, we can also celebrate right now your 19-year anniversary for your fabulous Astroblog.
So greetings, Ian.
Can you tell us, mate, what’s up in the sky for July?
Ian: After that introduction, I am blushing! But there’s quite a bit going on. For those of you who are actually interested in my biology and toxicology stuff, I strongly suggest you read The Conversation, where I semi-regularly put up articles about toxicology, biochemistry, and quite often, toxins.
Tonight, all eyes are on the sky, and this is a very special episode celebrating the 10 years. Now, back in 2016 when we started the evening sky, we had Jupiter in Leo heading towards the horizon, and Mars and Saturn bracketing the head of Scorpius. This month, it’s a little bit different. We are losing Jupiter and Mercury from the evening skies, which have been entertaining us for the past month. Venus is climbing higher towards Leo, which is where Jupiter was 10 years ago. Then in the morning, we’ve got Mars and Saturn putting on a nice show for us. So we’ve got lots to look forward to this month, just like we did 10 years ago.
The July Moon Phases & Earth Phases
Ian: Right. So like always, we’re going to start off with the Moon:
- July 8: Last Quarter Moon (Ideal for stargazing in the evening)
- July 14: New Moon (Ideal for stargazing at any time of the night)
- July 21: First Quarter Moon
- July 30: Full Moon
- Moon at Perigee (Closest to Earth): July 13
- Moon at Apogee (Furthest from Earth): July 26
Now, as I’m recording this, we’re experiencing solstice here in the Southern Hemisphere. The nights are at their longest and days are at their shortest. Next month on the 7th of July, Earth will be at Aphelion, where it’s furthest from the sun. Of course, this doesn’t necessarily mean very much in terms of the seasons, because while we experience winter at Aphelion, for the Northern Hemisphere—where they’re enjoying summer—the Earth is still furthest from the sun. It’s the angle of the Earth that’s doing all the heavy lifting. We’ll talk about that another day.
Evening Skies: Mercury, Venus, and Jupiter
Ian: Let’s go straight to the skies. Mercury is still visible below Jupiter at nautical twilight at the beginning of the week. However, by the end of the week, it’s lost in the twilight and will return to the morning skies at the end of this month.
Venus is really obvious now. It’s climbing higher in the evening sky and spends July passing through Leo. On the 9th and the 10th, it’s just 1° (around about a finger width) from Leo’s brightest star, the first-magnitude Regulus (otherwise known as Alpha Leonis). Then on the 17th, Venus is 8° above the planet, and the 3-day-old waxing crescent moon is halfway between Regulus and Venus, making a very nice sight.
Brendan: Yep.
Ian: Jupiter, which has been dominating the skies for months now, is visible in the early evening, setting just after nautical twilight at the beginning of the month. It’s very low above the northwestern horizon at twilight. On the 15th, Jupiter and the thin crescent moon are visible together, low above the horizon at civil twilight. After that, Jupiter is lost in the twilight glow. To see the 15th and the thin crescent moon, you’re going to need a clear, level horizon, like the ocean or the desert, to see it properly.
Morning Skies: Mars, Uranus, and Saturn
Ian: Now, let’s go to the morning skies. Mars is above the eastern horizon at nautical twilight in the morning. In fact, it’s above the eastern horizon at astronomical twilight, but it’s much higher at nautical twilight. Mars is in Taurus, and it’s between the Pleiades and the Hyades. From the 3rd to the 6th, the red planet will be less than 1° from Uranus.
Theoretically, Uranus is visible to the unaided eye, but it’ll be a faint dot—though very easily seen in binoculars. On the 4th and the 5th, Uranus and Mars are at their closest at less than 0.5° apart. They’re visible together in both binoculars and medium telescope eyepieces, and the contrast in colour will be quite nice. Again, the pair are midway between the Pleiades star cluster and the Hyades star clusters. Uranus, Mars, and the Pleiades will fit into a binocular field—and Mars and Uranus, of course, will fit into a binocular field. They’re not necessarily the same binocular field; you may have to do a little juggling around to get them just on the edge.
On the 11th, the crescent moon is very close to the Pleiades, with Mars nearby. Then from the 8th to the 10th, Mars is near a second eye called Aldebaran, forming one eye of Taurus the Bull, with Mars forming the other. On the 11th, the crescent moon is below Mars, forming a rough line with Mars and Aldebaran. You may need to be looking at nautical twilight for this. At astronomical twilight, the moon may be a bit too low to the horizon for you to see.
Brendan: Yep.
Ian: Again, last month the best planet dance was in the evening. The planet dance has now transferred to the morning skies.
Now, Saturn is in the evening skies in July, just for about mid-month. It’s rising about 11:30 p.m. in the eastern sky. On the 6th, the planet is at the point in its orbit known as the Western Quadrature. This is where the Sun-Earth angle is 90°. On the 8th, Saturn is about 7° from the last quarter moon, and that will look very nice in the early morning.
On the 28th, the ringed planet’s apparent path against the star field reverses as the world begins its retrograde track heading toward September opposition. Remember, the retrograde motion is occurring because Earth is beginning to overtake the planet in our orbit. So September will be a good time to get ready to start looking for Saturn in telescopes. It is actually very good in telescopes now—the rings are opening up—but it’ll be at its biggest and brightest in September.
Brendan: Excellent.
Deep Sky, Constellations & Meteors
Ian: The Corona Borealis still hasn’t gone bang. We’ll let you know if it happens.
Brendan: Of course not. Of course not.
Ian: You may be noticing that Scorpius the Scorpion is becoming more prominent above the eastern horizon. It’s almost galaxy season with the Milky Way rising. Around 11 p.m. local time, Scorpius lies across the zenith with Sagittarius and the heart of the galaxy beneath.
If you get a pair of binoculars and start at the head of Scorpius—that’s the T-shape above the bright red star Antares—and scan down the curl of stars that forms the body of the Scorpion, you’ll come to a star grouping where the tail begins to curl around. This is the False Comet. The star grouping is dominated by Zeta 1 and 2 Scorpii. If you follow this down, just a bit below that are two very nice binocular clusters: Ptolemy’s Cluster and the Butterfly Cluster. If you head down from there towards the lid of the teapot of Sagittarius, you’ll see the Trifid Nebula just above the lid. Then, just to one side of the lid, you’ll see the very prominent globular cluster M22.
Now, looking south around astronomical twilight—that’s 90 minutes after sunset when the sky is really dark—the Southern Cross will be almost at its highest due south. If you look a bit below Alpha Crucis, almost halfway between the Southern Cross and the False Cross, is a little group of stars called Theta Carinae, which is the Southern Pleiades. Theta Carinae is the brightest star, and all around it is an A-shaped group of stars. Above that is the broad, fuzzy patch that is the Carina Nebula. The variable star, Eta Carinae, is at its heart, but you can’t see it even with binoculars. There’s a dark band across this nebulosity called the Keyhole Nebula, but it’s best seen with binoculars or a small telescope.
The position of the Southern Cross and the Pointers makes finding Omega Centauri easy. It is a magnificent globular cluster, possibly the best globular cluster in the sky. It forms the apex of a triangle, using Beta Crucis and Beta Centauri to find the base. If you follow those two up to make a triangle, you’ll find Omega Centauri at the apex.
Finally, we have the meteors: the Southern Delta Aquariids. This is a meteor shower that runs from 12 July to the 23rd of August, peaking on Sunday, July 30th. Now, the number of meteors depends on how high the radiant is above the horizon and how dark your sky is. The zenithal hourly rate of the Southern Delta Aquariids is 25 meteors per hour, but in practice, you’ll never see that many because the radiant will be some distance below the zenith. Also, unless you’re deep in the countryside, the darkness will be less than ideal, especially as the shower’s fairly faint.
Sadly, this year the full moon is on the 30th, so the peak rates will be almost completely flooded out by the brightness of the moon.
Brendan: Of course it will. Of course. Of course.
Ian: So the shower’s best seen from midnight to 3 a.m. This year, unless you’re really, really dedicated, I wouldn’t bother disturbing your sleep.
Brendan: Yep.
Ian: And so that’s what’s up in the sky for July.
Brendan: Very good, Ian. Now, do you have anything else for us for July?
Ian: I do. I have a tangent for you.
Brendan: Excellent.
The Tangent: In the Clouds (Dedicated to Jack)
Ian: Again, I’m going to start by saying that July 2026 marks 10 years of sharing our wonderful sky with you all. And it’s been a pleasure and a joy.
Brendan: Exactly.
Ian: But 2026 marks a sadder anniversary. My son Jack died in November 2016.
He was often a part of my sky adventures. I showed him a lunar eclipse when he was a toddler and for ages after, the moon was “Daddy’s moon.”
On Christmas, he excitedly brought a present to me. “It’s binoculars!” he announced proudly before I unwrapped it.
He was with us on a famous family road trip that passed through Siding Spring Observatory, and the iTelescope observatory facility.
For years after, one of the iTelescope scopes bore his name.
Now, Jack never followed me into science—he was a writer at heart—but he did win an award for launching Tasmania into space.
Brendan: Yep.
Ian: Now, we may have not shared science, but we did share a love of looking at the world in wonder. So I dedicate this anniversary edition of the tangent to Jack, and he was very good at making tangents.
Brendan: I’ll put a link to the tribute we made for Jack at the end of this episode, Ian.
Ian: In Tangents past, we’ve discussed sealed telescopes, dung beetles that navigate by the line of the Milky Way, lost constellations, ducks watching meteors, and people mistaking constellations for drones. But today, I’m going to go on up into the clouds.
Now, you know clouds are the bane of astronomers and astrophotographers—like when a cloud camped over the Cairns solar eclipse for me. This can be neatly summed up by a comic from The Oatmeal. The protagonist reads of a rare planetary conjunction, looks out the window to clouds. Then he reads of a rare meteor shower, looks out to clouds. Then he reads of a rare cloud formation and looks out to a sparkling clear sky. And that basically sums up the astronomical life!
But while clouds frustrate us, clouds can be beautiful. The towering cumulonimbus looks amazing. From my childhood bedroom, where I watched the moon rise through my dad’s binoculars, I could see them on the horizon lighting up like flashbulbs from the lightning inside. This brings back memories of lightning crackling over the cane fields. And who could forget the dramatic roll clouds heading towards Sydney in 2024?
You cannot help but be in awe of clouds caught glowing in the sunset. Even at night, a crescent moon riding the clouds is a thing of beauty, even if we do really want to get our best photography at the time. When the clouds are thin, you may see a 22-degree halo arc, a coloured ring around the sun or the moon. More rarely from Australia, thin ice clouds can produce sun dogs and other amazing coloured arcs. If you’re familiar with the famous medieval woodcut of armies fighting in the sky over Nuremberg in 1561, these “sky armies” may indeed have been sun dogs.
Of course, there’s also rainbows and, even more rarely, true moonbows. The 22-degree halo arc is sometimes called a moonbow, but it is not an actual moonbow. A moonbow is a true rainbow formed by the moon. But of course, because the moon is bright much more rarely than the sun is, it’s very hard to see them.
The point of this is that there is beauty in everything if you have eyes to see. The constant theme of this podcast is to look up. Rain or shine, there’ll be something to see, even if it is clouds.
Another theme is that we don’t look up enough, and people are no longer familiar with the sky. This is why people identify Venus as rescue flares, the moon as a UFO, Orion as a flight of drones, etcetera, etcetera. Sadly, this phenomenon also applies to clouds.
Now, that wretched hive of scum and villainy called Twitter is home not only to flat earthers, but also to “cloud shamers”—chemtrail conspiracy folks who think jet contrails are geoengineering experiments or poison. In the latest iteration, these folks are getting upset over normal clouds! Cirrus, stratus, cirrostratus, harrow and barrow clouds and more. Seeing perfectly normal and beautiful cloud formations, they see dreadful plots to block out the sun. It’s especially annoying when they look at a 22-degree halo arc—a beautiful and not incredibly common phenomenon—and go, “Look at this filth.” No, that’s really beautiful! That’s amazing. Why are you going on like this? Did these people never look up as kids? Did they never pay attention to cloud lectures in school? What?!
So once again, I’m going to heartily recommend the book, The Invention of Clouds: How an Amateur Meteorologist Forged the Language of the Skies. I’ve mentioned it before. I’m going to mention it again because it’s a really good book.
Brendan: It is.
Ian: It tells the story of Luke Howard. Back in December 1802, Luke Howard delivered a lecture that was to be the defining point in natural history and meteorology. He named the clouds. He didn’t just name them; he classified them in terms that remain familiar to us to this day. So again: cirrus, stratus, cumulus, nimbus—we’re all familiar with these, unless, of course, you happen to be a cloud shamer.
Now, this new and precise nomenclature sparked worldwide interest and captured the imaginations of some of the century’s greatest figures in the fields of art, literature, and science. Goethe, Constable, and Coleridge were amongst those who came to admire Howard’s vision of an aerial landscape. These artists legitimised the elevation of this new classification of nomenclature, and meteorology fast became a respectable science. I should emphasise that Goethe was not only a poet, but also a serious scientist who did a lot of work on the basic subject of colour.
Howard’s classification remained untouched for ages. In fact, we’ve only just now added new cloud types, including one called asperitas. This is a wave-like cloud structure that makes it look like the world is underwater. And this is amazing! The cloud shamers see none of this as they look at the sky. They see just fear, not beauty.
So when we look up and we see our much-hoped-for comet, eclipse, or meteor shower blocked by clouds, let’s take a moment to cast that disappointment aside and look for the hidden wonder in the clouds. And as ever, look up.
Brendan: Excellent, Ian. And we don’t need to shake our hands at it.
Ian: This is true. We do not need to shake our hands at it. Sometimes when you go out and the sky is not only so black you can’t see anything, but it’s raining on you and you’re soggy… then you go, “Yeah, you may be able to find beauty in everything, but there’s some things that you just get too wet to worry about.”
Brendan: Excellent. Well, we won’t call this episode Old Man Shakes His Fist at the Sky.
Ian: No, look, I’m used to people not being familiar with astronomical objects. But come on, it’s the sky! It’s the sky. It’s absolutely something you should be seeing every day.
Brendan: Yeah, look, I described you earlier as an avid astronomer. I think the word “avid” is quite inadequate.
Ian: It’ll do, it’ll do.
Closing & Anniversaries
Brendan: Okay, Ian, well, thank you very much. This is our 10-year anniversary show, and I can see no reason why we can’t aim to keep going for another 10 years.
Ian: Yeah, well, I fully plan to be here in another 10 years. It’s too much to see. We’ve got the Apophis flyby, we’ve got the solar eclipse in Australia coming up… there’s too much to do to not be here, and too many things to see. It keeps on changing. We keep on finding new things to see.
Brendan: Exactly. Well, we’ll keep on doing it, Ian “Astroblog” Musgrave. Next year, we’ll also be celebrating the 20th year of the Astroblog website that you’ve maintained for so far 19 years. Next year, 20 years.
Ian: Yep, next year, 20 years. That’s going to be pretty amazing. We may also want to note parenthetically that Archie is 15 years old. So the parrot, which has been the background to many of my talks, is 15 years old this year. So there you go.
Brendan: Fantastic. So it’s roughly in between. We’ve got 10, 15, 19. Lots of good anniversaries. Excellent. Well…
Ian: Clear skies. Keep looking up.
Brendan: Exactly. Keep looking up.
And as promised, here’s a link to our tribute to Jack. I still remember Jack through my daughter’s composition of Stairway to Heaven on piano, violin and cello. For listeners, a live recording is still up at: tinyurl DOT com FORWARD SLASH jackstribute
All lowercase, all one word, no apostrophe.
That’s tinyurl DOT com / jackstribute
… and to discover the wealth of Ian’s Pharmacology and toxicology posts in “The Conversation” go to tinyurlDOTcom FORWARD SLASH ianmusgrave.
Once again, all lowercase, all one word
And in two weeks, we have a great in-depth interview for you when we’re speaking with Kovi Rose, a fantastic multi-wavelength astrophysicist at the University of Sydney and the CSIRO. Kovi has made a breakthrough discovery leading his international team—including astronomers from the United States, China, Canada, Spain, Israel and Australia—to find the Rosetta Stone in a star system on the very border of our Milky Way.
And remember, Astrophiz is free, ad-free and unsponsored.
Keep looking up. Clear skies.
SFX audio: Radio Waves!