Star Diary: 17 to 23 October, 2022
The Orionids meteor shower peaks this week, and Mercury passes by the binary star Porrima in our weekly stargazing guide.
What's in the night sky of the week of 17 to 23 October, 2022.
Ezzy Pearson This autumn Sky at Night Magazine's Masterclass series returns with a new set of online talks all about stargazing. Over three sessions we'll be joined by expert astronomers. He'll talk us through a different aspect of observing, then stay on hand to answer all of your questions. On the 29th of September. Learn how to navigate across the stars and constellations. Then take a tour of the Moon as we get to grips with the lunar landscape on the 27th of October and finally check in with the neighbours on the 1st of December and learn how to observe the planets. And if those dates don't work for you, don't worry. They'll all be available on demand after the talk. Tickets cost £15 each or you can save yourself £9 by getting all three at once. Visit www.skyatnightmagazine.com and click on the Virtual Events tab at the top of the page for more details and to book your tickets now.
Chris Bramley Hello and welcome to Star Diary, the podcast from the makers of BBC Skyline Magazine. You can subscribe to the print edition of the magazine or visiting www.skyatnightmagazine.com or to our digital edition by visiting on iTunes or Google Play.
Ezzy Greetings listeners and welcome to Star Diary, a weekly podcast guiding you around the best things to see in the northern hemisphere's as night sky. In this episode, we'll be covering the coming week from 17th to 23rd of October. I'm Ezzy Pearson, the magazine's features editor. Unfortunately, our reviews editor, Paul Money, who usually joins us on the podcast, couldn't be with us this week, but I'm still here to give you your weekly rundown of all the best things to see in the night sky. And to kick us off we're going to start on 17th October when a magnitude -0.4 Mars is going to lie just north of the Crab Nebula. So we talked a little bit about this at the end of last week's podcast, and so you might want to go back and listen to that for some more details. But the Crab Nebula is a fairly dim nebula. It's plus 8.4 in magnitude, which means you will need a telescope to be able to see it. However, with Mars just north of it, it does make it a good chance to try and photograph that nebula. We always like seeing your photographs, so please do send them over to us. You can find details about how to do that at www.skyatnightmagazine.com. So if you do manage to capture a photograph, please do let us know. That will be visible throughout the night. So you will have lots of chances to be able to see it. Moving forward onto 18th October. We are going to have another star this time in the morning sky. Regular listeners will know that quite often Paul laments the fact that sometimes you need to get up early in the morning to be able to see some of these astronomical sites. And unfortunately, that's the case for Mercury this week. Mercury is going to lie about 0.8 degrees away from the binary star Porrima, also known as Gamma Virginis. The magnitude of Mercury will be -0.9, so it will be nice and bright to be to be able to see. As always, when it comes to looking at the inner planets do be careful. They are closer to the Sun, which means they tend to occur around either sunset or Sun up in this case. So make sure that you make a note of when your local sunrise time will be, because we don't want you to be looking at Mercury through binoculars and then accidentally catch a glimpse of the Sun because that can hurt your eyes. So be very, very careful. Never look at the Sun directly through optics or with the naked eye. So on the 19th, I'm going to take this opportunity to highlight something that does happen once every week. It does. As I said, it happens every week, which is why we don't tend to talk about it on the podcast. But it is an interesting thing that I know a lot of people are interested in, and that is the transits of the moons Europa and Ganymede across the planet Jupiter. So Jupiter has four Galilean moons, they're called because they were discovered by Galileo back in the 17th century. And these planets go around Jupiter, and when they pass in front, we can see them moving across the planet's disk. They are very easy to see. You can see them with just a pair of binoculars, though they are best viewed through a small telescope or something like that. And when they pass in front, you can see not just them but also their shadows as they pass across the disk of the moon. Ganymede it takes seven days to go around Jupiter, whereas Europa takes 3.5 days. And what that means is that once a week they sync up and you can see both of them going across together. And this week that is going to be on 19th October. So Ganymede will be transiting as the planet comes up at around about 5:30pm in the evening. Meanwhile, Europa will be going from 5:15pm to 7:40. Europa's shadow will be going across from 6:10 to 9:00 o'clock. And then finally Ganymede's shadow will disappear off the view of Jupiter at about 8:30pm. So any time that you are looking from when you can first see Jupiter in the night sky all the way through to about 9:00 in the evening, you should be able to see either a moon or shadow transiting across Jupiter. So there's a lot of chance to be able to see something nice and early in the evening. You also might want to keep an eye out for another moon that's going to be near Jupiter, and that's Io, which will actually be eclipsed by the planet. It's going to pass behind the planet at about 6:30 and then will reappear about 9:00. So if you are out there looking at Jupiter and admiring the view anyway, maybe keep a little eye out for Io as it blinks out of view and disappears behind the planet. Then finally, we are going to end off the week on 21st October with a meteor shower. A meteor showers are always great things to be able to see. They are very accessible ways to start accessing the night sky. So if you have someone that you want to get involved in astronomy, maybe this will be the chance and it's going to be the Orionids meteor shower and that's going to peak at 7 p.m. BST on 21st October. You'll be able to see something either side of that. So if the weather doesn't cooperate on the 21st, maybe keep an eye out on the 20th, on the 22nd, there will still be a relatively decent rate of meteors on those nights. That said, the Orionids isn't one of the most prolific meteor showers throughout the year. It's got what's called a zenithal hourly rate or ZHR of about 20 meteors per hour. What that means is, if under perfectly perfect conditions, if you were looking straight up in the night sky, if the atmosphere was behaving itself. If your eyesight's really good, you could probably see about 20 meteors per hour. That's almost certainly not going to be the case. Life never cooperated like that. And so you're probably actually going to see a lot less than that. You might only see a handful, sort of five or ten meteors over the entire hour. To give yourself the best chance of being able to see them, it's really important to properly acclimatise your eyes and dark adapt to the darkness. And the best way to do this is to get yourself away from all forms of light that you can. If you can go to a dark sky site, that's great. But it might just be a question of going to your local park or something like that, or even, you know, that corner of your back garden where you are shielded away from all of the streetlights around you. Give yourself as long as you can, 10, 20 minutes, perhaps even an hour, to properly allow your eyes to adapt. And you'll be able to see hopefully all of these meteor streaking. They are called the Orionids because they appear to come from the constellation of Orion. So if you traced all of the meteors back, you would find that they are all pointing towards Orion. That point is called the radiant, where they all appear to come from. And the radiant in this case is actually going to be just close to Orion's left shoulder, which is the star Betelgeuse. And you don't actually want to be looking right at that. That's actually where the meteor trails are going to be shortest because they're coming straight towards you. You actually want to look about 90 degrees away from that point, so find Orion and then turn a right angle away. And that should be where you're trying to look. So 90 degrees away. That's where the trails will be the longest and you'll get the best view. You also might want to look to the South because there are some very good constellations in that part of the sky. So you'll have something to look at as you dark adapt and as you wait for these meteors to appear. It's a great group activity. It's a great way to get kids involved in the night sky and is also going to be good because the moon's not going to be rising until about 4:00 in the morning. So you've got a lot of life time in the evening to be able to see them before that comes and starts ruining everything with its big bright self and blocking out all of the dim meteors.
Ezzy So to go back again on 17th October, we've got Mars by the Crab Nebula on 18th October Mercury is going to be making and its acquaintance with the binary star, Porimma. Then on the 19th we have Europa and Ganymede transiting across Jupiter. And finally on the 21st we have the Orionids meteor shower. So there's lots to get up for next week. And if you want to find out even more about what's going to be coming up in the next weeks night sky be sure to subscribe to the podcast where we will give you your weekly guide to everything there is to see. Until then, goodbye.
Ezzy If you want to find out even more spectacular sites that will be gracing the night sky throughout the 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. 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 the detailed star charts to help you track your way across the night sky from all of us here at BBC Sky and Night Magazine. Goodbye.
Chris Bramley Thank you for listening to this episode of Star Dairy podcast from the makers of BBC Sky at Night Magazine. For more of our podcasts, visit our website at skyatnightmagazine.com Or head to ACast, iTunes or Spotify.