The ringed planet will be high in the sky this week, making it a great time to spot the gas giant. Find out how to see the sight for yourself by listening to this week’s episode of Star Diary, the podcast from the makers of BBC Sky at Night Magazine.
Subscribe to the Star Diary podcast
Chris Bramley: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the digital edition of the magazine by visiting iTunes, Google Play, or Apple News, or to the print edition by visiting skyatnightmagazine.com.
Ezzy Pearson: Greetings listeners. And welcome to Star Diary, a weekly guide to the best things to see in the Northern Hemisphere's night sky. As we are based here in the UK, all times are in BST. In this episode, we'll be covering the coming week from 5 to 11 August. I'm Ezzy Pearson, the magazine's features editor, and I'm joined today by Katrin Raynor an ,astronomer and astronomy writer.
Hello Katrin.
Katrin Raynor: Hi Ezzy, how are you doing?
Ezzy: I'm doing well. So what have we got to look forward to in this week's night sky?
Katrin: Well, the Moon is starting to wax again this week and now is a great time to set your sights on crater Albertegnius. This week is also the best time to view the Perseid meteor shower before its peak on the 12th into the 13th.
And we also have two minor planets opposition. And let's not forget noctilucent clouds, although they are starting to tail off now that we are getting into August, but I'm gonna shoehorn just one more mention of NLCs into this.
Chris: We'll keep mentioning them as long as we can.
Katrin: We could just mention them every week anyway, couldn't we? Just till next year, next year. I think people might turn off at that point. So moonrise on 5th, new Moon occurred yesterday on 4th, and this evening after sunset a 1% lit waxing Moon is low on the west northwest horizon in the evening twilight. And if you have an unobstructed view in this direction, grab your binoculars to locate the Moon and see bright Venus shining close by, but you're gonna have to be quick because both the Moon and Venus set around 40 minutes after the Sun.
And on 9th is our apogee, in other words, its furthest point in its elliptical orbit from Earth and is the Sun. a whopping 405,297km away from us.
Ezzy: That's quite far.
Katrin: It is, isn't it? It's very far. Compared to when it's closest, it's about 350?
Ezzy: It's about 50,000 is the, the difference between nearest and closest, which is a lot.
Katrin: It's a distance you can't really fathom.
Chris: But it's about, you know, sort of like 10% ish.
Katrin: Yeah, and I think, obviously then it just kind of brings to the forefront then, doesn't it? About the orbit of the Moon as well. It's obviously not a perfect circular orbit, you know, it's varying in its distance.
Ezzy: No matter how much ancient astronomers tried to make it be a perfect circle, it's not. It's very not. It's actually very few perfect circles when it comes to orbital mechanics. They're almost all ellipses.
Katrin: Yes, orbital mechanics. I'm sure that's something that sounds very complicated.
Ezzy: Oh, it is.
Katrin: So yeah, I'll just stick with everything's in an elliptical orbit. It's fine.
And on 10 August we have the 33% lit waxing Moon near Spica, a variable star, and the constellation of Virgo. So they're going to form a lovely pair in the evening sky. So if you want to have a look at these two, locate the Moon setting along the southwestern sky and the bright Spica will be close by.
My speaker is the brightest star in Virgo and shines at a magnitude of less than +1.0, so if, you're not going to miss it. Then obviously you're going to see the Moon anyway, because that's going to be quite bright.
So Spica is actually a really special star. It's got a long observational history, as you would expect.
It's a star that is thought to give Hipparchus, a Greek astronomer, the data that led him to discover the precession of the equinoxes, which is the gradual changing in the direction of the Earth's rotation axis. And the temple in Thebes it was built with this orientation towards the star.
Ezzy: Yes. So the precession basically the Earth's axis – if you imagine it's sort of spinning on its axis and that axis does what's called precesses.
Basically it sort of wobbles like a top, a spinning top that's starting to go and it takes about 30,000 years to go around once. It's something like that. So it's a long change, but if you're paying very, very close attention to the star as over long periods of time, people do notice that, yes, actually they do appear to be slightly shifting.
Katrin: I think as well, sometimes it's like easy to forget. Well, for me anyway. You know, that what we're seeing in the night sky and hearing about Greek astronomers using particular stars to reach certain conclusions, you kind of forget, oh yeah, actually, you know, thousands and thousands of years ago there were people looking at the night sky and formulating hypothesis or proving things correctly. It's amazing.
Ezzy: They didn't necessarily have the tools to make the most precise measurements.
Katrin: Not at all.
Ezzy: But they found all kinds of strange and wonderful ways to be able to keep track of all of these things because it was very important to people, partly just because that's how people used it to navigate and tell time, but also a lot of religious significance at the time as well. So it's very important. The star's been important to a lot of people for a very long time.
Katrin: That's amazing, isn't it? When you think about, yeah, things like Stonehenge, and it is amazing, and something I think I feel like I should read more up on. The history of astronomy.
So 11 August. So, August's top lunar feature in this month's issue of the Sky at Night is the Crater Albategnius. It is best seen on the night 11 and 12th. So, check out the latest issue for more information on observing this crater.
Just to give you a brief overview, it is located in the central highlands, and there is a lovely central peak on the crater floor to see.
And Crater Klein overlies its southwestern rim. Now there's a really fun clair obscure effect which will be visible around first quarter, which is on 12th. So you can look for the face of Albertegnius. Now this effect is caused by the shadow of the crater's uneven eastern rim cast onto the crater floor.
Yeah, you're going to be able to see a profile of the face on the crater floor, which is pretty cool.
I actually feel like sometimes I can see two faces because I think the Crater Klein that overlies the rim and one of the satellite craters and the central peak kind of looks like Pob. Do you remember Pob, the old 80s children's TV program?
Ezzy: I've got the picture up in front of me and I I do know who you mean from that .
Katrin: So you've got Pob and the face on Albategnius. So yeah, two faces in one there .
So Solar System wise on 6th at around 2:00 AM bright, Jupiter will shine at a magnitude of -2.0, whilst Mars and Aldebaran shine a magnitude of less than +1.0 to form a lovely celestial triangle in the early morning sky.
Now minor planet 7 Iris, the fourth brightest object in the asteroid belt, is at opposition on the 6th at 7:40PM and it's also going to be at perigee, so it's making its closest approach to Earth.
It'll be shiny at magnitude +8.1, so you're going to need your binoculars or a telescope to see this star-like object. And it's currently in the constellation of Aquarius, which is well above the horizon for much of the night, and Iris will be at its highest point above the southern horizon at midnight.
Just below Iris, near the constellation of Capricorn, is another main asteroid called 16 Psyche, and it's also at opposition. Now Psyche is 200km across and is named after the Greek goddess for the soul. Psyche meaning soul. And it is much dimmer than Iris, it's shining a magnitude of +9.6. So again, you're going to need some equipment to see this.
And if the name sounds familiar, well, just last October, NASA launched a spacecraft to orbit and study Psyche in order to learn more about the origin of planetary cores. The plan is to orbit the asteroid from August 2029 through to late 2031. And the asteroid is the heaviest known M type asteroid and composed of metals.
It's thought to be an exposed iron core of a failed protoplanet and if this is interesting to you and you want to read more about Psyche then you can head over to the Sky at Night website.
Ezzy: I love asteroids and meteors and meteorites and things like that. It's that sort of concept of that you can actually, bits of it, that have made it back to Earth and you can pick up and you can hold something that's been just hanging around in space for billions of years.
Katrin: It's incredible, isn't it? It's like, again, it's just something that doesn't feel real, you know, we said last week, didn't we, about when you look through the telescope, oh, it doesn't feel real. But physically, it's like, this came from space.
Ezzy: Yeah, because a lot of meteorites, basically, they're either the material that never made it into being planets that came together and formed these sort of big rocky bodies.
Some of them, like Psyche, started to become a planet, or a protoplanet, but then there was a lot of stuff flying around in the early Solar System and they sometimes smashed into each other.
And when that happened, all of the bits got split off and sent flying through the Solar System, most ending up in the asteroid belt. I have a small meteorite collection.
Katrin: I was going to ask, do you have a meteorite collection?
Ezzy: I do, because as some people might know, I actually went out to... back in 2013 there was the Chelyabinsk meteor.
Katrin: Oh yeah.
Ezzy: And I actually went out to Chelyabinsk.
Katrin: Did you?
Ezzy: Yes, so I've got one of those that sits on my... sits on my desk.
Katrin: So did you go to find some?
Ezzy: Yeah.
Katrin: All right, okay.
Ezzy: Yeah, so I was actually there, I was shooting a documentary and we went hunting for them through the snowfields and. It was one of those things when you first got it in your hand it feels so very heavy because it's even though that particular meteorite was not very rich in metals.
It has a lot of metal in it compared to a regular earth rock and it feels so much heavier. And then you get one of the ones which is completely metal, meteorite. And it feels like a lump of steel because it's pretty much what it is.
Katrin: What was your method in finding them and, like, picking them up?
Ezzy: So, one of the best ways to try and find meteorites is to have it fall somewhere that's either completely covered in snow or is a desert, like a pristine sandy desert. That's your best way to find them.
In Russia, it was February, it was the middle of winter, so everywhere's covered in this pristine layer of snow. And so if you see, like, a hole in the snow or a rock lying on top of the snow, you know that didn't jump up from nowhere. It must have come down from the sky.
So you look for those holes and then you kind of like dig around them to clear away the snow and then sort of keep scooping down until you come up with the rock.
Katrin: Was there lots of other people there doing the same thing?
Ezzy: Yeah, there was lots of people that went out in the very, very cold weather digging through the snow.
There's actually a lot of people, because I used to know a lot of geologists, and that was one of the things that geologists often went and did was they went to like Svalbard or somewhere like that and went and dug up all of these asteroids.
Katrin: That is a very cool story.
Ezzy: But anyway, we'd better be cracking on with what's up in this night sky.
Katrin: We went off on a tangent there, but it's relevant, it's a relevant tangent, it's fine.
If you are out and you want to spot Iris or Psyche, just a reminder, they're going to look like starlike points of light, so they're going to be tricky to find if you don't know what you're looking for. So between 9 and 15 August, the Perseid meteor shower is very active and it's going to reach its peak next week from the night of 12th into dawn on 13th.
Between now and then, you know, it's a great time to see the meteors, probably the best time obviously to see them. So the meteors radiant is in the northern portion of the constellation of Perseus and this is where the name originates. So you should hopefully be able to see trails and trains left behind by bright meteors and maybe even a fireball or two.
And this is one of the best meteor showers of the year, so let's hope there are no clouds to interfere with it.
Ezzy: Always the hope.
Katrin: Yeah, exactly. It'd always be typical, isn't it? Something happens in the sky, it's cloudy. There's a great meme actually on the internet about, greatest astronomical event of the year, and it's all clouds.
Ezzy: Yeah, and it's just a picture of clouds.
Katrin: Yeah, and it's like rare clouds to be seen in the sky, and it's just a clear sky. It's just it's typical. It sums it up very well.
On 9th August we also have a double shadow transit to look forward to. So two of Jupiter's moons, Io and Ganymede's shadows will transit Jupiter between 3:45AM and 4:26AM. If you missed them last week, you've got another chance on 9th. So you'll be able to see this transit using small to medium and of course larger aperture telescopes.
And on 10th, Saturn reaches its highest position at 3:30AM due south, under dark skies at an altitude of around 30º.
So if you are out in the early hours observing minor planets, Iris and Psyche, take a look at the ringed planet to the east of Aquarius.
There's actually a very exciting occultation happening in 11 days time on 21st when the planet will be occulted by the Moon. But again, Mary, I'm sure will tell you all about that in that week's episode.
And just to round off, noctilucent clouds! Woo! This may be the last time that they may get mentioned in Star Diary, I'm not quite sure. But, you know, I mentioned this last week. They're starting to tail off now, we're entering August, so we're gonna see them less and less.
Seen them since June. If you haven't spotted them yet, then you may still. I'm not quite sure, to be honest, but I'm just going to mention them anyway. Goodbye, NLCs, from Katrin Raynor.
Ezzy: Goodbye, NLCs, but you did put on a good show. So definitely, there's a lot of things to see in the night sky. We will be back next week with Mary and even more stargazing highlights for people to get to grips with.
So do subscribe to the podcast if you'd like to hear those. But to summarise, this week again.
On 5 August, try and catch the thin crescent Moon and Venus low in the evening twilight.
Then on 9th, the Moon is going to be at apogee.
On 10th, the 33% waxing Moon is near to the variable star Spica.
On 11th, August's top lunar feature in the Sky at Night Magazine is a crater called Albategnius, so keep an eye out for that one.
Moving on to the planets, on 6th at around about 2:00AM in the morning, the bright planet Jupiter, Mars and the star Aldebaran will form a lovely celestial triangle in the early morning sky.
Minor Planet 7 Iris is also going to be at opposition on 6 August. It will also be at Perigee. You will need binoculars or a telescope to see that, it will just appear like a star.
The Perseid meteor shower is becoming increasingly active, between 9 and 15th will be at peak of its activity.
It'll actually peak next week into 12th or 13th, but at the tail end of this week it is still worth keeping an eye out for those meteors.
Also, the 9th, two of Jupiter's moons, Io and Ganymede, will have shadow transits across the face of Jupiter between 3:45AM and 4:26AM.
On 10 August, Saturn will also be reaching very high in the night sky, so definitely worth keeping an eye out for the ringed planet as well.
And finally, NLC season is just winding up, so it is really your last chance to get out there and try and see those noctilucent night shining clouds. If you do see any, please do let us know at contactus@skyatnightmagazine.com. We always like to hear from you guys.
And that's all from us for this week. We'll be back next week, and we hope to see you all again soon.
If you want to find out even more spectacular sights that will be gracing the night sky this month, be sure to pick up a copy of BBC Sky at Night magazine, where we have a 16 page pull out sky guide with a full overview of everything worth looking up for throughout the whole month.
Whether you like to look at the Moon, the planets, or the deep sky, whether you use binoculars, telescopes, or neither, our Sky Guide has got you covered, with detailed star charts to help you track your way across the night sky. From all of us here at BBC Sky at Night Magazine, goodbye.
Chris: Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky Night Magazine, which was edited by Lewis Dobbs.
For more of our podcasts, visit our website at skyatnightmagazine.com/podcasts, or head to Spotify, iTunes, or your favourite podcast player.
Listen to next week's episode "The Perseids meteor shower peaks (Star Diary 12 to 18 August 2024)"
