1 00:00:02,000 --> 00:00:04,960 I can't see one single star. Can you, George, anywhere? 2 00:00:04,960 --> 00:00:07,240 Being a British stargazer has never been easy. 3 00:00:07,240 --> 00:00:09,960 Yes. And there is Saturn. Is it gone? Oh, no. 4 00:00:09,960 --> 00:00:12,920 Just as I got it on the cross wires it blacked right out. 5 00:00:12,920 --> 00:00:16,280 How absolutely typical. There's nothing we can do about it. 6 00:00:16,280 --> 00:00:18,320 It's half one. It's raining. 7 00:00:18,320 --> 00:00:21,560 And the satellite photo shows cloud for the rest of the night. 8 00:00:21,560 --> 00:00:24,480 So all we can do is shrug and hope for better luck tomorrow. 9 00:00:26,720 --> 00:00:29,360 I love it, Chris. Always the optimist. I do try. 10 00:00:29,360 --> 00:00:32,000 Over the years on The Sky At Night, we've tried to bring 11 00:00:32,000 --> 00:00:34,160 you the experience of stargazing. 12 00:00:34,160 --> 00:00:36,880 But as you can see, with the British weather, even with the best 13 00:00:36,880 --> 00:00:39,000 will in the world, things can go horribly wrong. 14 00:00:39,000 --> 00:00:41,520 How many of us have planned a night of stargazing only 15 00:00:41,520 --> 00:00:44,120 for it to be ruined by the weather forecast? 16 00:00:44,120 --> 00:00:47,120 So today we're here in the gorgeous Oxford Botanic Garden, 17 00:00:47,120 --> 00:00:50,000 with a slightly different kind of show for you. 18 00:00:50,000 --> 00:00:52,000 We'll be offering you alternative, 19 00:00:52,000 --> 00:00:53,720 equally dazzling spectacles 20 00:00:53,720 --> 00:00:55,840 for when the nights are short, 21 00:00:55,840 --> 00:00:57,640 and the stars are hiding. 22 00:00:57,640 --> 00:00:59,600 BOTH: Welcome to The Sky At... 23 00:00:59,600 --> 00:01:01,320 ..Day. ..Day. 24 00:01:30,000 --> 00:01:32,120 Now, there's never any guarantee with the weather. 25 00:01:32,120 --> 00:01:34,360 But these long summer days do provide an opportunity 26 00:01:34,360 --> 00:01:36,400 to discover astronomical wonders 27 00:01:36,400 --> 00:01:38,280 hiding in plain sight. 28 00:01:38,280 --> 00:01:39,440 Absolutely. 29 00:01:39,440 --> 00:01:42,720 Now, the star of today's show is definitely our local star, 30 00:01:42,720 --> 00:01:44,160 the sun. 31 00:01:44,160 --> 00:01:46,640 So as well as telling you how to observe it safely, 32 00:01:46,640 --> 00:01:48,960 here's what we've got coming up. 33 00:01:50,320 --> 00:01:54,000 In this programme, we'll speak to the scientists who have flown 34 00:01:54,000 --> 00:01:56,440 space probes into the sun's atmosphere. 35 00:01:56,440 --> 00:02:01,800 We couldn't power the spacecraft without the power supply melting. 36 00:02:01,800 --> 00:02:05,720 We couldn't design a heat shield that wouldn't burst into flames. 37 00:02:05,720 --> 00:02:08,520 And we meet the amateurs gazing up at the sun 38 00:02:08,520 --> 00:02:10,720 from down here on Earth. 39 00:02:10,720 --> 00:02:14,840 We have exploding prominences that are erupting from the sun. 40 00:02:14,840 --> 00:02:18,960 We see plasma shapes on the edge of the sun that look like monsters. 41 00:02:18,960 --> 00:02:21,520 George Dransfield is back hunting 42 00:02:21,520 --> 00:02:24,400 for micrometeorites in the sunshine. 43 00:02:24,400 --> 00:02:28,200 Wow. There's a chunk of magnetic stuff there! 44 00:02:28,200 --> 00:02:31,920 There must be some micrometeorites in here. 45 00:02:31,920 --> 00:02:34,760 And we look west to Bristol, for a sunset 46 00:02:34,760 --> 00:02:37,560 masterclass from Dr Hannah Wakeford. 47 00:02:37,560 --> 00:02:39,840 As we move towards sunset, 48 00:02:39,840 --> 00:02:43,160 the sun is moving through a longer distance of atmosphere. 49 00:02:43,160 --> 00:02:47,480 So all we end up with is this beautiful, red, orange sunset. 50 00:02:50,800 --> 00:02:53,840 But first, to the star of the show. 51 00:02:53,840 --> 00:02:55,520 Despite being our local star, 52 00:02:55,520 --> 00:02:57,120 and our constant companion 53 00:02:57,120 --> 00:03:00,680 for over four and a half billion years, there are still many aspects 54 00:03:00,680 --> 00:03:02,840 of the sun that remain a mystery. 55 00:03:02,840 --> 00:03:06,640 Chris spoke to Justin Kasper from the Parker Solar probe, 56 00:03:06,640 --> 00:03:11,120 Nasa's record-breaking mission that flew into the sun's atmosphere. 57 00:03:13,840 --> 00:03:17,640 Liftoff of the mighty Delta four heavy rocket with Nasa's 58 00:03:17,640 --> 00:03:19,400 Parker Solar probe. 59 00:03:19,400 --> 00:03:22,240 A daring mission to shed light on the mysteries 60 00:03:22,240 --> 00:03:24,040 of our closest star, the sun. 61 00:03:34,200 --> 00:03:36,200 Well, Justin, thank you for joining us. 62 00:03:36,200 --> 00:03:39,760 Where did the idea for the Parker probe come from? 63 00:03:39,760 --> 00:03:43,480 Before Nasa even existed in the United States, 64 00:03:43,480 --> 00:03:46,240 there were some studies that were carried out that asked 65 00:03:46,240 --> 00:03:51,440 the question, "If you could send a satellite into space, what kind 66 00:03:51,440 --> 00:03:52,720 "of science would you do?" 67 00:03:52,720 --> 00:03:56,680 And one of the ideas was the concept of a solar probe. 68 00:03:56,680 --> 00:03:58,960 And so, solar probe - 69 00:03:58,960 --> 00:04:03,640 the goal was send the spacecraft close enough into the sun. 70 00:04:03,640 --> 00:04:05,920 You could dip into its atmosphere, 71 00:04:05,920 --> 00:04:08,360 figure out why its atmosphere was so hot, 72 00:04:08,360 --> 00:04:11,520 and what exactly it is that happens in the atmosphere 73 00:04:11,520 --> 00:04:15,840 that makes these jets that we call the solar wind appear and flow 74 00:04:15,840 --> 00:04:17,280 through interplanetary space. 75 00:04:17,280 --> 00:04:20,680 So why did it take so long between the initial idea 76 00:04:20,680 --> 00:04:23,440 and the launch of the Parker Solar Probe? 77 00:04:23,440 --> 00:04:25,920 We had a few technical challenges. 78 00:04:25,920 --> 00:04:29,200 First, it was just technically impossible. 79 00:04:29,200 --> 00:04:31,560 We couldn't power the spacecraft 80 00:04:31,560 --> 00:04:34,040 without the power supply melting. 81 00:04:34,040 --> 00:04:37,360 We couldn't design a heat shield that wouldn't burst into flames. 82 00:04:37,360 --> 00:04:40,880 And then over time, we started figuring out new tricks. 83 00:04:40,880 --> 00:04:45,760 So using Venus, instead of going out to Jupiter to get close to the sun, 84 00:04:45,760 --> 00:04:49,960 using special solar panels that can survive with high 85 00:04:49,960 --> 00:04:53,720 temperatures, and actually pumping water behind them to cool them 86 00:04:53,720 --> 00:04:55,840 off so they don't melt when we're near the sun. 87 00:04:55,840 --> 00:04:58,560 But of course, the whole point of doing this is to take some 88 00:04:58,560 --> 00:05:00,880 scientific instruments along with you. 89 00:05:00,880 --> 00:05:03,920 I know you're involved in... It's Sweap, isn't it? 90 00:05:03,920 --> 00:05:05,520 Your instrument. 91 00:05:05,520 --> 00:05:08,560 Tell us about that instrument and what it's trying to do. 92 00:05:08,560 --> 00:05:11,200 It's a lot like recording the weather on Earth. 93 00:05:11,200 --> 00:05:13,600 You know, you want to know how windy it is, 94 00:05:13,600 --> 00:05:15,640 which way the wind's going, what... 95 00:05:15,640 --> 00:05:18,600 Maybe what the pressure is and how it's changing. 96 00:05:18,600 --> 00:05:23,080 And so the Sweap investigation measures the main particles 97 00:05:23,080 --> 00:05:24,680 in the sun's atmosphere, 98 00:05:24,680 --> 00:05:28,840 and we scoop up samples of the sun's atmosphere each time we fly by. 99 00:05:28,840 --> 00:05:32,600 And then the sensors on the spacecraft analyse those samples, 100 00:05:32,600 --> 00:05:34,360 and they report back. 101 00:05:34,360 --> 00:05:36,400 "OK, here's the temperature, the direction. 102 00:05:36,400 --> 00:05:37,920 "There was this much helium. 103 00:05:37,920 --> 00:05:39,600 "The electrons were headed this way. 104 00:05:39,600 --> 00:05:41,680 "The helium was headed that way." 105 00:05:41,680 --> 00:05:43,000 And, well, you're now there. 106 00:05:43,000 --> 00:05:46,840 You've had a few orbits close to the sun. 107 00:05:46,840 --> 00:05:48,440 What have we found out so far? 108 00:05:48,440 --> 00:05:50,400 We flew through that outer boundary, 109 00:05:50,400 --> 00:05:52,200 we call that the Alfven surface, 110 00:05:52,200 --> 00:05:53,920 for the first time last year. 111 00:05:53,920 --> 00:05:55,400 That was very exciting. 112 00:05:55,400 --> 00:05:58,880 But one of the surprises was the surface. 113 00:05:58,880 --> 00:06:01,840 While it was very clear when we were above or below it, 114 00:06:01,840 --> 00:06:04,560 it had to be very wrinkled to explain 115 00:06:04,560 --> 00:06:06,760 how we were able to move in and out. 116 00:06:06,760 --> 00:06:11,280 So different kinds of solar wind coming from different regions 117 00:06:11,280 --> 00:06:16,880 on the sun seemed to push the sun's atmosphere closer, further. 118 00:06:16,880 --> 00:06:18,840 So this, you know, big surprise, 119 00:06:18,840 --> 00:06:21,240 it's not just a simple spherical shell 120 00:06:21,240 --> 00:06:22,840 it's some very complicated surface. 121 00:06:22,840 --> 00:06:25,600 And what did your particle experiment record, as you were going 122 00:06:25,600 --> 00:06:28,880 in and out of that surface? Did you see a change? 123 00:06:28,880 --> 00:06:32,280 What we weren't expecting, that was amazing to see, 124 00:06:32,280 --> 00:06:35,960 is the pressure exerted by the particles in the sun's 125 00:06:35,960 --> 00:06:38,400 atmosphere in that region. 126 00:06:38,400 --> 00:06:41,520 So the pressure of the ions, the pressure of the electrons, 127 00:06:41,520 --> 00:06:44,600 that pressure was 100 times smaller 128 00:06:44,600 --> 00:06:47,440 than the pressure exerted 129 00:06:47,440 --> 00:06:49,240 by the sun's magnetic field. 130 00:06:49,240 --> 00:06:51,440 Those particles were really trapped, 131 00:06:51,440 --> 00:06:53,080 and forced to move wherever 132 00:06:53,080 --> 00:06:55,520 the magnetic field decided it wanted to move. 133 00:06:55,520 --> 00:06:59,000 The magnetic field was calling all the shots, and it was a real 134 00:06:59,000 --> 00:07:00,320 surprise to see that, 135 00:07:00,320 --> 00:07:03,400 even though we were still, you know, millions of kilometres 136 00:07:03,400 --> 00:07:04,480 away from the sun. 137 00:07:04,480 --> 00:07:08,560 What are you most looking forward to in what's left of the mission? 138 00:07:08,560 --> 00:07:11,440 What are the results that really excite you? 139 00:07:11,440 --> 00:07:14,440 So, what's going to happen now over the next couple of years, 140 00:07:14,440 --> 00:07:17,880 is we're going to get, you know, nearly twice as close. 141 00:07:17,880 --> 00:07:21,040 And I really think we're going to be able to make that connection, 142 00:07:21,040 --> 00:07:25,760 finally, between the surface of the sun is doing something, 143 00:07:25,760 --> 00:07:29,920 and that's resulting in this super hot atmosphere and accelerating 144 00:07:29,920 --> 00:07:31,760 the wind in these given ways. 145 00:07:31,760 --> 00:07:35,080 And I think we're going to unlock those secrets. Excellent. 146 00:07:35,080 --> 00:07:37,480 It's really exciting stuff and a great mission. 147 00:07:37,480 --> 00:07:39,800 Thank you so much for telling us about it. 148 00:07:39,800 --> 00:07:41,440 And we'll catch up soon. 149 00:07:41,440 --> 00:07:43,200 My pleasure. Great talking to you. 150 00:07:47,360 --> 00:07:50,560 Unlike the stars in the night sky, we can see our star 151 00:07:50,560 --> 00:07:51,680 all year round. 152 00:07:51,680 --> 00:07:55,240 And moreover, we can observe its atmosphere and its surface. 153 00:07:55,240 --> 00:07:58,240 We don't even need the Parker Solar Probe to do this. 154 00:07:58,240 --> 00:08:01,480 We went to Bath to meet Simon Holbeche and discover 155 00:08:01,480 --> 00:08:05,800 how he's showing his community the sun in a whole new light. 156 00:08:09,600 --> 00:08:12,560 Looking directly at the sun is extremely dangerous, 157 00:08:12,560 --> 00:08:15,520 and can permanently damage your eyes. 158 00:08:15,520 --> 00:08:20,520 But there are ways to safely observe the sun using specialist filters. 159 00:08:20,520 --> 00:08:24,000 Simon uses these at his observation events. 160 00:08:25,120 --> 00:08:27,560 I was about nine or ten when I got my first telescope 161 00:08:27,560 --> 00:08:29,360 and managed to take it outside, 162 00:08:29,360 --> 00:08:31,160 and start trying to find things 163 00:08:31,160 --> 00:08:33,120 in the night sky. 164 00:08:33,120 --> 00:08:35,280 I endured hours of frustration, 165 00:08:35,280 --> 00:08:38,160 trying to find any objects in the night sky. 166 00:08:38,160 --> 00:08:40,360 I even thought the moon was going to be really easy. 167 00:08:40,360 --> 00:08:42,520 Turned out it was really tough as well. 168 00:08:42,520 --> 00:08:44,400 But the biggest leap was actually 169 00:08:44,400 --> 00:08:46,680 joining a local astronomical society. 170 00:08:51,920 --> 00:08:55,680 For me, discovering outreach was a really important part of my life. 171 00:08:55,680 --> 00:09:00,160 I learnt that I could actually help out other people directly, 172 00:09:00,160 --> 00:09:03,440 to inspire other people, to get them to look at the world 173 00:09:03,440 --> 00:09:04,760 in a different way. 174 00:09:04,760 --> 00:09:07,200 Are the two dots next to each other? Yeah. 175 00:09:07,200 --> 00:09:08,680 You see it? 176 00:09:08,680 --> 00:09:11,480 And so it's absolutely delightful today when we can come out 177 00:09:11,480 --> 00:09:15,800 in the sunshine and use the sun as our reason for being outside. 178 00:09:15,800 --> 00:09:17,680 It's an astronomical object, 179 00:09:17,680 --> 00:09:19,480 and we can look up and wonder 180 00:09:19,480 --> 00:09:21,800 about the science behind it. 181 00:09:21,800 --> 00:09:26,840 So fingers crossed, the sun will eventually find a way through. 182 00:09:26,840 --> 00:09:29,120 So today we've been using several different methods 183 00:09:29,120 --> 00:09:30,680 to look at the sun. 184 00:09:30,680 --> 00:09:32,640 We've been using a pair of binoculars, 185 00:09:32,640 --> 00:09:34,440 and the light goes through one side 186 00:09:34,440 --> 00:09:39,080 of the binoculars, and we project it onto a piece of card. 187 00:09:39,080 --> 00:09:41,480 OK, that is a sunspot. 188 00:09:41,480 --> 00:09:43,320 So the sun has different layers. 189 00:09:43,320 --> 00:09:45,800 The base layer that we can see is called the photosphere, 190 00:09:45,800 --> 00:09:49,520 but there's an atmosphere above it called the chromosphere. 191 00:09:49,520 --> 00:09:53,840 So what we've got is some specialist telescopes to be able to see 192 00:09:53,840 --> 00:09:56,640 those two individual layers. 193 00:09:56,640 --> 00:09:59,800 We've put a filter on the front, which takes out most 194 00:09:59,800 --> 00:10:01,880 of that really harmful sunlight. 195 00:10:01,880 --> 00:10:06,680 So 99.999% of the light, with some of our filters. 196 00:10:06,680 --> 00:10:09,440 And that allows us to put an ordinary eyepiece 197 00:10:09,440 --> 00:10:12,560 behind the telescope and actually stare down the photosphere 198 00:10:12,560 --> 00:10:13,600 of the sun. 199 00:10:19,120 --> 00:10:22,480 We can see, instead of one big splodge, that you might see 200 00:10:22,480 --> 00:10:26,200 with binoculars, we can see the individual sunspots. 201 00:10:28,400 --> 00:10:29,520 It's a great time 202 00:10:29,520 --> 00:10:31,200 to look at the sun at the moment. 203 00:10:31,200 --> 00:10:34,200 We're just coming out of a solar minimum, and we're building 204 00:10:34,200 --> 00:10:35,720 up towards solar maximum. 205 00:10:35,720 --> 00:10:40,080 So come the next couple of years, by 2024, 2025 206 00:10:40,080 --> 00:10:43,920 the sun should look like myself when I was a spotty teenager, 207 00:10:43,920 --> 00:10:46,160 absolutely covered in sunspots. 208 00:10:46,160 --> 00:10:50,600 And we'll be able to see it all changing very dynamically. 209 00:10:50,600 --> 00:10:53,960 But what really interests me is that there's an atmosphere 210 00:10:53,960 --> 00:10:57,400 above the sun, the chromosphere, and that gets really excited 211 00:10:57,400 --> 00:11:00,320 by all the energy that's coming through, all these sunspots, 212 00:11:00,320 --> 00:11:01,840 and it's in constant turmoil. 213 00:11:01,840 --> 00:11:04,920 So using the red light telescope, we're actually able 214 00:11:04,920 --> 00:11:06,560 to look at the solar prominences. 215 00:11:06,560 --> 00:11:10,960 All the stuff that's coming out of the sunspots is arching 216 00:11:10,960 --> 00:11:14,520 through, making beautiful fountains on the edge of the sun, contrasting 217 00:11:14,520 --> 00:11:16,480 with the darkness of space. 218 00:11:19,240 --> 00:11:20,720 Hello! 219 00:11:20,720 --> 00:11:24,520 So you get some people that will just look through and go, "Oh, OK. 220 00:11:24,520 --> 00:11:26,120 "Oh, that's interesting." 221 00:11:26,120 --> 00:11:28,560 Do you want to have another look? 222 00:11:28,560 --> 00:11:32,360 Occasionally you'll get someone who's absolutely inspired, 223 00:11:32,360 --> 00:11:36,160 where they'll just look through and they just can't stop looking. 224 00:11:36,160 --> 00:11:38,400 They want to have another look. 225 00:11:39,920 --> 00:11:43,080 And we've got a queue of people behind them. 226 00:11:44,080 --> 00:11:46,560 So it's one of those moments in life where you've got to say, 227 00:11:46,560 --> 00:11:48,080 "I really want to encourage you, 228 00:11:48,080 --> 00:11:50,040 "but let's move you to the next telescope," 229 00:11:50,040 --> 00:11:52,600 or just hang around 15 more minutes, 230 00:11:52,600 --> 00:11:54,840 and I'll give you another look. 231 00:11:54,840 --> 00:11:58,400 I know it's been a successful observing event because people 232 00:11:58,400 --> 00:12:00,280 have talked at the eyepiece. 233 00:12:00,280 --> 00:12:02,800 It's spinning faster, and that kind of... 234 00:12:02,800 --> 00:12:04,240 But more importantly, 235 00:12:04,240 --> 00:12:07,240 it's when they're walking away. 236 00:12:07,240 --> 00:12:09,360 With their parents or together, 237 00:12:09,360 --> 00:12:11,680 and just having a general chitchat 238 00:12:11,680 --> 00:12:14,280 about what they've seen, and how exciting it's been. 239 00:12:14,280 --> 00:12:17,080 And I know that that conversation is going to continue 240 00:12:17,080 --> 00:12:19,280 in the car, back at home and potentially 241 00:12:19,280 --> 00:12:21,200 in the school or in the workplace. 242 00:12:21,200 --> 00:12:23,880 And people are actually going to be looking up and enjoying 243 00:12:23,880 --> 00:12:26,320 the sky much more than they were the day before. 244 00:12:33,440 --> 00:12:37,280 There are many champions of astronomy up and down the country. 245 00:12:37,280 --> 00:12:39,720 But if you want to get involved, get in contact 246 00:12:39,720 --> 00:12:42,320 with your local astronomical society. 247 00:12:42,320 --> 00:12:46,320 Now, I'm sure you remember George Dransfield, the astrophysicist 248 00:12:46,320 --> 00:12:48,440 who went on an adventure to Antarctica. 249 00:12:48,440 --> 00:12:50,760 Well, she's back, and this time 250 00:12:50,760 --> 00:12:53,040 she's on a mission for The Sky At Night. 251 00:12:57,840 --> 00:13:01,040 Besides awesome stargazing conditions, there's another thing 252 00:13:01,040 --> 00:13:02,760 Antarctica was perfect for. 253 00:13:02,760 --> 00:13:03,880 Oh, my goodness. 254 00:13:03,880 --> 00:13:05,320 Look at that waddle! 255 00:13:07,160 --> 00:13:08,760 No, not penguins. 256 00:13:08,760 --> 00:13:09,800 Meteorites. 257 00:13:10,960 --> 00:13:15,560 Now, sadly, I never got to search the snow for little space rocks. 258 00:13:15,560 --> 00:13:18,800 But whilst hunting for daytime activities to engage my students 259 00:13:18,800 --> 00:13:22,360 with astronomy, I heard that I could find micrometeorites 260 00:13:22,360 --> 00:13:24,200 right here in Birmingham. 261 00:13:25,200 --> 00:13:28,800 And, apparently, the best place to find them is on a roof. 262 00:13:36,400 --> 00:13:40,920 As meteors tear through the Earth's atmosphere, tiny particles break 263 00:13:40,920 --> 00:13:44,520 off, raining down from the sky onto mountains, forests 264 00:13:44,520 --> 00:13:47,080 and even urban rooftops. 265 00:13:47,080 --> 00:13:51,800 Tonnes of this cosmic dust sprinkle the Earth every day, meaning 266 00:13:51,800 --> 00:13:53,680 these tiny micrometeorites 267 00:13:53,680 --> 00:13:55,400 are more common than you might think. 268 00:13:58,280 --> 00:14:00,920 So I'm hoping to find some micrometeorites in all this dust 269 00:14:00,920 --> 00:14:04,800 I'm sweeping up, but it would take me ages to find them manually. 270 00:14:04,800 --> 00:14:08,000 Fortunately, micrometeorites like their meteor parents, 271 00:14:08,000 --> 00:14:11,120 have a really high iron and nickel content so I can find them 272 00:14:11,120 --> 00:14:13,800 with the help of my magnet. 273 00:14:13,800 --> 00:14:15,560 So much dust. 274 00:14:15,560 --> 00:14:18,600 There must be some micrometeorites in here. 275 00:14:21,640 --> 00:14:25,360 Wow. There's a chunk of magnetic stuff there. 276 00:14:25,360 --> 00:14:28,280 Not all of this is going to be micrometeorites, 277 00:14:28,280 --> 00:14:30,840 but what I'm going to do now that I found the magnetic stuff, 278 00:14:30,840 --> 00:14:34,920 is give it a bit of a wash and see what's in there. 279 00:14:34,920 --> 00:14:37,400 Micrometeorites, also known as 280 00:14:37,400 --> 00:14:40,200 Cosmic Spherules or even Stardust, 281 00:14:40,200 --> 00:14:42,280 aren't a recent discovery. 282 00:14:42,280 --> 00:14:46,960 But the fact that anyone can find them anywhere is a new idea 283 00:14:46,960 --> 00:14:49,440 pioneered by Norwegian geologists 284 00:14:49,440 --> 00:14:51,880 Jon Larsen and Jan Braly Kihle. 285 00:14:53,160 --> 00:14:54,960 OK, I've been at this for a while now, 286 00:14:54,960 --> 00:14:57,480 and I think I might have actually found one, 287 00:14:57,480 --> 00:14:59,080 but I'm not entirely sure. 288 00:14:59,080 --> 00:15:01,920 So I'm going to get in touch with the guys who pioneered 289 00:15:01,920 --> 00:15:04,200 this method, and see what they say about it. 290 00:15:06,680 --> 00:15:10,600 So thank you guys so much for dialling in and helping out. 291 00:15:10,600 --> 00:15:14,520 So, I've been trying to search for micrometeorites all day, 292 00:15:14,520 --> 00:15:17,320 and turns out it's not as easy as I thought. 293 00:15:17,320 --> 00:15:20,480 So how did you guys first figure that you could search 294 00:15:20,480 --> 00:15:23,320 for micrometeorites in an urban environment? 295 00:15:23,320 --> 00:15:26,000 13 years ago, in the summer of 2009, 296 00:15:26,000 --> 00:15:28,520 I was having breakfast outdoors 297 00:15:28,520 --> 00:15:33,480 on the white table on my veranda, 298 00:15:33,480 --> 00:15:35,280 and I suddenly noticed 299 00:15:35,280 --> 00:15:38,160 that there was something strange, 300 00:15:38,160 --> 00:15:40,480 because there was a shiny dot. 301 00:15:40,480 --> 00:15:43,840 So I picked it up on my finger and I thought, "Wow, 302 00:15:43,840 --> 00:15:45,400 "this is not a rock." 303 00:15:45,400 --> 00:15:48,760 It triggered my curiosity big time. 304 00:15:48,760 --> 00:15:53,320 And from then on, it was no return. 305 00:15:53,320 --> 00:15:56,440 And you guys haven't just been, like, finding them. 306 00:15:56,440 --> 00:15:58,960 But you've come up with a really cool, special technique 307 00:15:58,960 --> 00:16:00,640 for photographing them. 308 00:16:00,640 --> 00:16:04,000 And I've seen some, like, otherworldly pictures you've taken. 309 00:16:04,000 --> 00:16:07,520 So how did you design that photographing technique? 310 00:16:07,520 --> 00:16:10,120 So this is... This is the set-up. 311 00:16:12,040 --> 00:16:13,680 Oh, wow. 312 00:16:13,680 --> 00:16:17,640 So it's... The footprint is very, very small. 313 00:16:17,640 --> 00:16:19,280 It's extremely compact. 314 00:16:19,280 --> 00:16:23,720 Each of the images that you have seen on the net consists 315 00:16:23,720 --> 00:16:27,880 of between 200 and 1,000 single images. 316 00:16:27,880 --> 00:16:31,600 In some cases, up to 1,200, 1,300 images 317 00:16:31,600 --> 00:16:33,960 at this very high magnification. 318 00:16:33,960 --> 00:16:37,320 The focus depth is extremely shallow. 319 00:16:37,320 --> 00:16:39,160 And what we are doing 320 00:16:39,160 --> 00:16:42,720 is we are staging the space rocks, 321 00:16:42,720 --> 00:16:45,880 like any portrait photographer 322 00:16:45,880 --> 00:16:48,160 would do with putting lights, 323 00:16:48,160 --> 00:16:50,880 and play with light and shadow. 324 00:16:50,880 --> 00:16:54,160 In order to make the best results. 325 00:16:54,160 --> 00:16:56,520 Wow. So what are the main categories, then? 326 00:16:56,520 --> 00:17:00,000 What are the main groups that they kind of fall into? 327 00:17:00,000 --> 00:17:02,520 Depending upon the entry angle, etc, 328 00:17:02,520 --> 00:17:06,520 that creates the entire variety 329 00:17:06,520 --> 00:17:12,200 of types, from the unmelted ones until the completely melted ones. 330 00:17:12,200 --> 00:17:17,840 And in between there are, let's say, a handful of main types, 331 00:17:17,840 --> 00:17:21,480 like, when they start to crystallise, 332 00:17:21,480 --> 00:17:26,640 it curves olivine crystals, 333 00:17:26,640 --> 00:17:29,000 and they get smaller and smaller. 334 00:17:29,000 --> 00:17:35,360 And up to very fine-grained crystal lumens. 335 00:17:35,360 --> 00:17:39,360 All these micrometeorites, they are not two alike. 336 00:17:39,360 --> 00:17:44,120 You recently met the person who went all the way to Antarctica 337 00:17:44,120 --> 00:17:47,080 to find these micrometeorites. 338 00:17:47,080 --> 00:17:49,760 And then... So, how did that story go? 339 00:17:49,760 --> 00:17:54,800 At that time, the consensus in academia was that the cosmic dust 340 00:17:54,800 --> 00:17:58,120 particles, of course, you cannot find them. 341 00:17:58,120 --> 00:18:01,400 So Michel Maurette, he thought, 342 00:18:01,400 --> 00:18:06,400 "Well, in the cold desert at the South Pole, 343 00:18:06,400 --> 00:18:08,000 "it's below zero all the time. 344 00:18:08,000 --> 00:18:11,560 "If a particle lands there, it might be frozen. 345 00:18:11,560 --> 00:18:17,800 "So it might be an archive of frozen micrometeorites within the blue 346 00:18:17,800 --> 00:18:19,280 "ice of Antarctica." 347 00:18:19,280 --> 00:18:23,160 And he went there, and then he found them. 348 00:18:24,400 --> 00:18:25,760 Last month, 349 00:18:25,760 --> 00:18:28,760 I visit the old master, 350 00:18:28,760 --> 00:18:31,680 and we paid a tribute to him, 351 00:18:31,680 --> 00:18:35,840 thanked him for the work, and just for fun, 352 00:18:35,840 --> 00:18:40,680 I took some magnetic samples outside his house, 353 00:18:40,680 --> 00:18:43,880 and in that dust there was one micrometeorite. 354 00:18:43,880 --> 00:18:45,800 No, really? Yeah. 355 00:18:45,800 --> 00:18:48,480 Yes, yes. Oh, wow. 356 00:18:48,480 --> 00:18:52,720 So the guy who went to the end of the world 357 00:18:52,720 --> 00:18:55,600 to find the micrometeorites, he actually had it just 358 00:18:55,600 --> 00:18:57,280 outside his own house. 359 00:18:57,280 --> 00:19:00,320 That is really, really fascinating. And I absolutely love that story. 360 00:19:00,320 --> 00:19:02,000 So this is what I found today on the roof 361 00:19:02,000 --> 00:19:03,400 of the University of Birmingham. 362 00:19:03,400 --> 00:19:04,640 So what do you think? 363 00:19:04,640 --> 00:19:06,320 Am I onto something? 364 00:19:06,320 --> 00:19:08,400 OK, so the size should be OK. 365 00:19:08,400 --> 00:19:10,480 And the colour is OK. 366 00:19:10,480 --> 00:19:12,880 But the black material 367 00:19:12,880 --> 00:19:15,000 on the top is something 368 00:19:15,000 --> 00:19:17,000 that we do not regularly observe. 369 00:19:17,000 --> 00:19:18,920 But I think that the lack... 370 00:19:18,920 --> 00:19:21,440 If that's... If you have been on the roof 371 00:19:21,440 --> 00:19:23,240 and found only one, 372 00:19:23,240 --> 00:19:27,640 it tells me that you have looked in not the right places, 373 00:19:27,640 --> 00:19:31,600 in the right way, because any roof anywhere, even 374 00:19:31,600 --> 00:19:36,040 in remote places, will be so filled with spherules. 375 00:19:36,040 --> 00:19:37,120 OK, brilliant. 376 00:19:37,120 --> 00:19:40,640 So I didn't find one this time, but now I am equipped with better 377 00:19:40,640 --> 00:19:44,200 information, and I'm motivated to go out there and try again. 378 00:19:44,200 --> 00:19:46,800 Well, thank you again, so much for your time, both of you. 379 00:19:46,800 --> 00:19:49,880 It's been an absolute pleasure to meet you. OK. Thank you, likewise. 380 00:19:53,040 --> 00:19:56,120 If you want to get involved in that meteoritic daytime activity 381 00:19:56,120 --> 00:19:58,760 or the Project Stardust Citizen Science programme, then head 382 00:19:58,760 --> 00:20:01,680 on over to our website where we've put a guide on how to get started. 383 00:20:01,680 --> 00:20:05,600 Now with his favourite daytime observations, 384 00:20:05,600 --> 00:20:09,400 it's Pete - a man who's finally got a good night's sleep. 385 00:20:12,520 --> 00:20:15,720 Now, it probably comes as no surprise that the sky at day 386 00:20:15,720 --> 00:20:18,800 can be just as cloudy as the sky at night. 387 00:20:18,800 --> 00:20:22,160 But what might be a surprise are the number of things 388 00:20:22,160 --> 00:20:26,120 of an astronomical nature that you can see during the day. 389 00:20:26,120 --> 00:20:29,200 The sun is an obvious candidate, of course. 390 00:20:30,680 --> 00:20:33,520 The moon can be seen, often, during the day. 391 00:20:33,520 --> 00:20:37,160 The problem with the moon, when the sun is up, is that it doesn't 392 00:20:37,160 --> 00:20:40,360 stand out quite as well as it does at night. 393 00:20:40,360 --> 00:20:43,400 So you have to know roughly where it is and you have to look 394 00:20:43,400 --> 00:20:46,760 that little bit harder. As well as the moon, 395 00:20:46,760 --> 00:20:49,200 there are the bright planets, of course. 396 00:20:49,200 --> 00:20:52,920 Venus can often be seen when it's far enough from the sun 397 00:20:52,920 --> 00:20:54,800 in a clear blue sky. 398 00:20:54,800 --> 00:20:58,920 Again, as long as you know where to look. Mercury can be seen 399 00:20:58,920 --> 00:21:02,400 with a telescope, and so can Jupiter and Saturn. 400 00:21:04,400 --> 00:21:07,240 But as well as the daytime objects 401 00:21:07,240 --> 00:21:09,440 you can see, there are other 402 00:21:09,440 --> 00:21:14,840 interesting phenomena, which are linked to the end of the day. 403 00:21:14,840 --> 00:21:18,640 And one in particular really stands out for me. 404 00:21:18,640 --> 00:21:22,840 When I was a boy, I read about what's called the green flash. 405 00:21:22,840 --> 00:21:27,440 This is an effect which occurs when the sun is really low 406 00:21:27,440 --> 00:21:30,200 down in the sky, close to the horizon, 407 00:21:30,200 --> 00:21:34,000 typically seen over a seaward horizon. 408 00:21:34,000 --> 00:21:38,520 The top of the sun is supposed to go a vibrant green. 409 00:21:38,520 --> 00:21:43,640 Well, it turns out that the atmosphere acts like a giant 410 00:21:43,640 --> 00:21:47,760 prism, and bright objects when they get low down, 411 00:21:47,760 --> 00:21:52,720 have their light split or spread into a spectrum of colour. 412 00:21:54,440 --> 00:22:00,680 Now the top of the bright object will have the blue-green part 413 00:22:00,680 --> 00:22:03,240 of the spectrum, whereas the bottom edge 414 00:22:03,240 --> 00:22:05,680 will show the redder part of the spectrum. 415 00:22:05,680 --> 00:22:07,800 So it's like all the colours have been spread out, 416 00:22:07,800 --> 00:22:11,440 with blue-green at the top and the red part at the bottom. 417 00:22:11,440 --> 00:22:15,200 Now, our atmosphere is really good at scattering blue light, 418 00:22:15,200 --> 00:22:17,200 so the blue component gets lost, 419 00:22:17,200 --> 00:22:22,240 which leaves a green fringe at the top and a red fringe at the bottom. 420 00:22:22,240 --> 00:22:25,640 Now, if you've got a bright object like the sun or even the moon, 421 00:22:25,640 --> 00:22:28,280 actually, as it's getting very low down, 422 00:22:28,280 --> 00:22:31,880 if the atmospheric conditions are correct, 423 00:22:31,880 --> 00:22:36,040 very low down, the atmosphere can act like a lens, 424 00:22:36,040 --> 00:22:38,560 cylindrical lens, which splits off that - 425 00:22:38,560 --> 00:22:42,160 what's called the green rim at the top of the sun or the moon. 426 00:22:42,160 --> 00:22:46,760 And it will create a gap between that bit of green 427 00:22:46,760 --> 00:22:49,200 and the object which has set. 428 00:22:50,320 --> 00:22:53,040 So that bit of green hangs above the horizon, 429 00:22:53,040 --> 00:22:56,280 and that is what is known as the green flash. 430 00:22:57,560 --> 00:23:00,560 I've been lucky enough to see the green flash 431 00:23:00,560 --> 00:23:02,040 a few times in my life. 432 00:23:02,040 --> 00:23:05,920 One of the most spectacular instances was from Chile, 433 00:23:05,920 --> 00:23:10,600 where the other worldly green colour was even more vivid to the eye 434 00:23:10,600 --> 00:23:13,720 than I was able to capture with my camera. 435 00:23:13,720 --> 00:23:16,320 It was a truly beautiful experience. 436 00:23:22,080 --> 00:23:25,440 Sailors used to say that, if you see a green flash, you're set 437 00:23:25,440 --> 00:23:27,320 up for fine weather the next day. 438 00:23:27,320 --> 00:23:28,800 Or someone's coming back 439 00:23:28,800 --> 00:23:31,800 from the dead, if you believe in pirate ghost stories. 440 00:23:31,800 --> 00:23:34,680 But what causes these spectacular sunsets? 441 00:23:34,680 --> 00:23:37,720 And can we learn to read them like the sailors did, to predict 442 00:23:37,720 --> 00:23:40,080 a fine night stargazing? 443 00:23:40,080 --> 00:23:43,560 Well, here's Dr Hannah Wakeford from the University of Bristol 444 00:23:43,560 --> 00:23:45,720 with a masterclass on sunsets. 445 00:23:57,760 --> 00:23:59,480 The Earth is one of a kind. 446 00:23:59,480 --> 00:24:01,760 Unlike if we were standing 447 00:24:01,760 --> 00:24:04,680 on the moon or Mercury where you'd see the blackness of space, 448 00:24:04,680 --> 00:24:07,040 here we have blue skies. 449 00:24:07,040 --> 00:24:10,360 That's caused by particles of gas 450 00:24:10,360 --> 00:24:14,040 in the atmosphere, scattering the white light from our star. 451 00:24:14,040 --> 00:24:16,400 But as we head towards sunset, 452 00:24:16,400 --> 00:24:19,720 that turns into a red-y orange colour. 453 00:24:19,720 --> 00:24:20,960 The sun hasn't changed. 454 00:24:20,960 --> 00:24:22,720 Our atmosphere hasn't changed. 455 00:24:22,720 --> 00:24:24,280 So what's happening? 456 00:24:24,280 --> 00:24:25,840 Let's go have a look. 457 00:24:37,040 --> 00:24:39,520 So this tank is going to act as our atmosphere. 458 00:24:39,520 --> 00:24:42,480 We've got water here, with a little bit of milk powder in it. 459 00:24:42,480 --> 00:24:46,480 This torch is going to act like our sun. When the sun 460 00:24:46,480 --> 00:24:48,480 is directly overhead, 461 00:24:48,480 --> 00:24:52,120 that light is being scattered in just the short 462 00:24:52,120 --> 00:24:53,440 wavelengths, the blue. 463 00:24:53,440 --> 00:24:56,960 So that is why we see the sky being blue. 464 00:24:56,960 --> 00:24:59,520 As we move towards sunset, 465 00:24:59,520 --> 00:25:02,720 the sun is moving through a longer distance of atmosphere. 466 00:25:02,720 --> 00:25:04,800 It has to go a longer way. 467 00:25:04,800 --> 00:25:06,080 So all of that blue light, 468 00:25:06,080 --> 00:25:08,440 and some of the other light is scattered away. 469 00:25:08,440 --> 00:25:12,640 So all we end up with is this beautiful red-orange sunset. 470 00:25:12,640 --> 00:25:16,840 You can see that here, where we start out blue right at the front. 471 00:25:16,840 --> 00:25:20,560 And then it slowly turns orange as it goes through the water, 472 00:25:20,560 --> 00:25:23,040 and we see our orange-red sunset. 473 00:25:25,800 --> 00:25:28,640 Now, that's the physics of how we get a sunset. 474 00:25:28,640 --> 00:25:31,640 But sunsets can actually be a good indicator 475 00:25:31,640 --> 00:25:33,040 of the weather to come. 476 00:25:33,040 --> 00:25:36,800 So if you find yourself out stargazing without the wonders 477 00:25:36,800 --> 00:25:40,080 of modern technology, you can use the old adage - 478 00:25:40,080 --> 00:25:42,400 "Red sky at night, shepherd's delight, 479 00:25:42,400 --> 00:25:44,720 "red sky in morning, shepherd's warning," 480 00:25:44,720 --> 00:25:46,040 to help you out. 481 00:25:46,040 --> 00:25:50,160 This is actually a fairly good indicator, especially 482 00:25:50,160 --> 00:25:52,120 for somewhere like the UK, 483 00:25:52,120 --> 00:25:57,440 and that's because between the latitudes of 30 and 60 degrees, 484 00:25:57,440 --> 00:25:59,560 we have westerly winds. 485 00:25:59,560 --> 00:26:04,640 If you have a red sky at night, shepherd's delight, there'll be some 486 00:26:04,640 --> 00:26:06,360 good stargazing for you. 487 00:26:06,360 --> 00:26:10,760 And that's because you've got a high pressure system on the west, 488 00:26:10,760 --> 00:26:14,600 and that means that you've got good weather incoming. 489 00:26:14,600 --> 00:26:17,960 However, if you see a red sky in the morning, 490 00:26:17,960 --> 00:26:20,080 that really is a shepherd's warning. 491 00:26:20,080 --> 00:26:23,560 That beautiful weather system has passed you already. 492 00:26:23,560 --> 00:26:25,200 It is in the east, 493 00:26:25,200 --> 00:26:28,080 so it's already blown over the UK, 494 00:26:28,080 --> 00:26:31,920 and that means you've got a low pressure system coming in. 495 00:26:31,920 --> 00:26:34,040 So the air is going to be rising, 496 00:26:34,040 --> 00:26:35,720 condensing into clouds, 497 00:26:35,720 --> 00:26:38,200 and you're going to get stormy, blustery weather 498 00:26:38,200 --> 00:26:39,960 like we've got today. 499 00:26:39,960 --> 00:26:44,480 So - red sky at night, shepherd's delight, great stargazing. 500 00:26:44,480 --> 00:26:46,640 Red sky in morning, shepherd's warning. 501 00:26:46,640 --> 00:26:48,600 Get your brollies out. 502 00:26:48,600 --> 00:26:51,680 Sunsets aren't just a predictor of weather. 503 00:26:51,680 --> 00:26:56,360 They can give you examples of things happening half a world away. 504 00:26:57,440 --> 00:27:01,600 A volcanic explosion will jettison particles into the atmosphere, 505 00:27:01,600 --> 00:27:05,080 causing the sunsets to become purple. 506 00:27:05,080 --> 00:27:09,480 If you're in the Arctic or Antarctic with beautiful, clear skies, 507 00:27:09,480 --> 00:27:12,360 you can sometimes see a sunset for days. 508 00:27:13,800 --> 00:27:16,240 But sunsets aren't unique to the Earth. 509 00:27:16,240 --> 00:27:19,880 We can also look at the sunsets from other planets. 510 00:27:19,880 --> 00:27:23,440 Mars, for example, has a blue sunset. 511 00:27:23,440 --> 00:27:26,840 We can go even further and look at the sunsets 512 00:27:26,840 --> 00:27:30,320 of exoplanets, planets that orbit other stars. 513 00:27:30,320 --> 00:27:33,280 And from this, we can learn more about their environments, 514 00:27:33,280 --> 00:27:36,880 more about what makes up their atmospheres. 515 00:27:36,880 --> 00:27:42,720 We've seen sunsets from bright greens to film noir, grey scales, 516 00:27:42,720 --> 00:27:44,640 and these indicate different things 517 00:27:44,640 --> 00:27:46,160 in the atmosphere, blocking 518 00:27:46,160 --> 00:27:47,680 and scattering that light. 519 00:27:47,680 --> 00:27:52,400 And from that, we can learn more about these distant alien worlds. 520 00:27:53,760 --> 00:27:55,840 Just imagine the possibilities. 521 00:27:55,840 --> 00:27:59,080 You will never see a sunset the same way again. 522 00:28:03,520 --> 00:28:05,680 I love a good sunset. Me too. 523 00:28:05,680 --> 00:28:08,240 In fact, I'm going to go back to using sunsets instead of apps 524 00:28:08,240 --> 00:28:09,760 to predict the weather. Really? 525 00:28:09,760 --> 00:28:12,120 I think I'm going to stick with the app. 526 00:28:12,120 --> 00:28:14,040 Oh, possibly wise, possibly. 527 00:28:14,040 --> 00:28:15,640 That's it for this month's programme. 528 00:28:15,640 --> 00:28:18,440 And I do hope we've giving you some ideas of things you can do 529 00:28:18,440 --> 00:28:21,640 when the clouds ruin your night stargazing. 530 00:28:21,640 --> 00:28:24,640 Next month, we'll be turning our attention back to the night sky, 531 00:28:24,640 --> 00:28:27,560 with the news that you've been waiting for since Christmas. 532 00:28:27,560 --> 00:28:31,280 The first images from JWST, our newest space telescope. 533 00:28:31,280 --> 00:28:34,000 We'll be following the story of JWST so far, 534 00:28:34,000 --> 00:28:37,240 and meeting some of the scientists that can't wait 535 00:28:37,240 --> 00:28:39,040 to get their hands on the telescope. 536 00:28:39,040 --> 00:28:40,240 We hope you'll join us. 537 00:28:40,240 --> 00:28:42,760 Until then, from Oxford's Botanic Garden... 538 00:28:42,760 --> 00:28:43,880 BOTH: Good afternoon. 539 00:28:45,920 --> 00:28:50,280 # But your momma always said, Look up into the sky 540 00:28:50,280 --> 00:28:52,200 # Find the sun on a cloudy day 541 00:28:52,200 --> 00:28:53,400 # On a cloudy day 542 00:28:53,400 --> 00:28:57,000 # But your momma always said Look up into the sky 543 00:28:57,000 --> 00:29:00,160 # Find the sun on a cloudy day 544 00:29:00,160 --> 00:29:02,360 # On a cloudy day 545 00:29:02,360 --> 00:29:05,360 # But your momma always said Look up into the sky 546 00:29:05,360 --> 00:29:08,160 # Find the sun on a cloudy day 547 00:29:08,160 --> 00:29:10,640 # On a cloudy day. #