News related to Stargazing

Greetings Junior Scientists, Scientists and citizens of this great big weird, wild and wonderful world in which we live. As always I’m your humble science communicator, the great Orbax, coming to you from the Department of Physics at the University of Guelph and I’d like to welcome you to our July 2025 Star Gazing Guide.

Last month was the summer solstice, and that means that even though it seems like the heart of summer, our nighttime hours are actually getting longer. Sunset's getting earlier this month, taking place at 9:06 p.m. on July 1st and creeping up to 8:44 on the 31st. Similarly, sunrise is also getting later, moving from 5:44 a.m. on the 1st to 6:10 on the 31st. And while that only gives us 9 and 1/2 hours to stargaze, there's still plenty to see in our July night skies. Let's start off this month by trying to identify some constellations that are visible around sunset, so you don't have to stay up too late. We'll also be on the lookout for a meteor or two and try to find out if the moon will be destroyed by an asteroid.

All this and more when you just take some time... to look up.

So, the Sun has just set. I want you to look directly above you and you'll see a very bright star. This star is Vega. 14,000 years ago, it was our north star. And you'll see it again as our north star if you're around in 12,000 years from now. It's part of an asterism known as the summer triangle that we've talked about before. Below Vega and then slightly to the West and then to the North are two of our largest constellations, Hercules and Draco. Hercules comes to us from Roman mythology based on Greek mythology based on the story of the Sumerian warrior Gilgamesh. As a matter of fact, the ancient Sumerians actually recognized this constellation thousands of years before Ptolemy. In many depictions Hercules stands victorious, standing upon the head of Draco the dragon, locked in eternal triumph. See if you can spot these two just after sunset high in the West junior scientists.

Our Full Moon this month is on July 10th.

Settlers commonly refer to the July Full Moon as the Buck Moon or Thunder Moon. The Anishinaabe of the Great Lakes refer to the July Moon as the Halfway Summer Moon, Abitaa-niibino-giizis, as the days have already started getting shorter after the Summer Solstice back in June. The Cree of central Canada call the July full Moon Opaskowipisim, the Feather Moulting Moon and the Mi'kmaw of the East coast also refer to this behaviour calling it Peskewiku’s, the Birds Shedding Feathers Moon.

The Delta Aquariids meteor shower occurs annually from July 12th to August 23rd with a peak this year on the evening of July 28th into the morning of the 29th. Emanating from the constellation Aquarius in the southeast, from which the shower gets its name, you should be able to see around 20 meteor per hour anywhere in the sky. With the crescent Moon setting just after dusk, we'll have dark skies all night with best viewing after midnight. Good luck, junior scientists.

Back in December 2024, an asteroid named YR4 was discovered by the Asteroid Terrestrial-impact Last Alert System in Hawaii. Scientists examining its flight path gave us some upsetting news - that there was a chance of this 'city killer' asteroid the size of a 10-storey building striking the Earth on December 22nd, 2032. Further data has confirmed that there's no longer any threat of this impact. However, there's still a 4.3% chance that it may strike the Moon!

What does that mean?

Well, let's start off with explaining what an asteroid is. Unlike comets, which are made of ice and dust, an asteroid is just a big rock floating through space, in this case, orbiting our sun.
Now, based on the data we've collected, there is a chance that asteroid YR4 could strike the Moon. And although it's been dubbed a 'city killer' here on Earth, there are no cities or wildlife or ecosystems to damage on the Moon.
So, while it would be quite the impact, it would simply result in another crater on the already heavily cratered surface of our Moon.
And where did all those other craters that are already there come from?
Well, most of those were formed by other asteroid impacts. Actually, the predicted flight path of YR4 shows that the impact, if any, would take place on the near side of the Moon.
Meaning that depending on where you are on the Earth at the time, you might actually be able to see the impact.

So, it makes a crater, but where does all that material that's ejected from the crater go? Well, some of that heads towards us here on Earth, but it burns up in our atmosphere as an incredible series of shooting stars and quite possibly the largest meteor shower that any of us will ever see. Now, it is possible that those same meteors could cause significant damage to any of our satellites or off-Earth missions occurring at the time, but we won't know much more until asteroid YR4 gets close enough to collect more data in 2028.

As we continue to gaze past the thin veneer of gas on this massive spinning rock on which we live, we see the universe unfold in myriad ways, spiraling through time and swirling with beauty.
We realize that it's all there, out there, if we just take some time... to look up.

See you next month, junior scientists, and don't forget to have a science-tastic day!

Special thanks to Royal City Science's own planetary geo-chemist, Dr. Glynis Perrett, for her help in preparing our star gazing guide. And the Royal Astronomical Society of Canada.