WEBVTT 00:00:07.969 --> 00:00:10.669 Howdy stargazers, and welcome to this episode 00:00:10.669 --> 00:00:14.369 of Star Trails. Drew here, and I'll be your guide 00:00:14.369 --> 00:00:17.449 to the night sky for the week starting June 1st 00:00:17.449 --> 00:00:21.469 through the 7th. This week, the rising summer 00:00:21.469 --> 00:00:24.489 triangle lets us know that warmer nights are 00:00:24.489 --> 00:00:27.829 ahead. We take a moment to explore a peculiar 00:00:27.829 --> 00:00:32.049 solar alignment in New York City known as Manhattan 00:00:32.049 --> 00:00:35.570 Hinge, and later we explore the parking lots 00:00:35.570 --> 00:00:39.850 of space known as the Lagrange Points. Whether 00:00:39.850 --> 00:00:42.310 you're tuning in from the backyard, the balcony, 00:00:42.509 --> 00:00:45.450 or just your imagination, I'm glad you're here. 00:00:45.929 --> 00:00:49.429 So find a cozy spot, let your eyes adjust, and 00:00:49.429 --> 00:00:52.270 let's see what the sky holds for us this week. 00:00:53.929 --> 00:00:57.570 The moon is currently waxing. Tonight it's in 00:00:57.570 --> 00:01:00.829 a crescent phase with about 6 % illumination. 00:01:01.490 --> 00:01:04.569 It will reach first quarter on June 3rd with 00:01:04.569 --> 00:01:07.329 the full moon arriving around the middle of next 00:01:07.329 --> 00:01:11.269 week. Venus is shining brilliantly at magnitude 00:01:11.269 --> 00:01:14.709 negative 4 and it's just reached its greatest 00:01:14.709 --> 00:01:18.750 western elongation, making it a prominent morning 00:01:18.750 --> 00:01:22.670 star in the eastern sky before sunrise. Saturn 00:01:22.670 --> 00:01:26.090 is still visible in the early morning sky, rising 00:01:26.090 --> 00:01:29.329 in the east during the predawn hours. While not 00:01:29.329 --> 00:01:32.329 as bright as Venus, it's distinguishable by its 00:01:32.329 --> 00:01:37.189 steady yellowish glow. Look westward after sunset 00:01:37.189 --> 00:01:40.409 tonight to spot a conjunction of the moon and 00:01:40.409 --> 00:01:44.109 Mars. The waxing crescent moon will appear close 00:01:44.109 --> 00:01:47.170 to Mars, offering a picturesque pairing for evening 00:01:47.170 --> 00:01:50.489 observers. Mercury is currently too close to 00:01:50.489 --> 00:01:53.269 the Sun to be easily observed, but it will become 00:01:53.269 --> 00:01:56.349 more visible in the evening sky later this month. 00:01:57.670 --> 00:02:00.489 As summer creeps closer, the night sky starts 00:02:00.489 --> 00:02:03.769 to show off its southern stars, and this week 00:02:03.769 --> 00:02:06.450 you'll have some real stunners to track down. 00:02:07.310 --> 00:02:09.889 Low in the southeast after dark, you'll spot 00:02:09.889 --> 00:02:13.610 the curve of Scorpius, one of the few constellations 00:02:13.610 --> 00:02:16.289 that actually looks like what it's named after. 00:02:16.620 --> 00:02:20.699 Its brightest star, Antares, whose name actually 00:02:20.699 --> 00:02:25.120 means rival of Mars, is a massive red supergiant 00:02:25.120 --> 00:02:28.719 nearing the end of its life, and like Mars, it 00:02:28.719 --> 00:02:32.500 glows with a deep, rusty hue. Just to the west 00:02:32.500 --> 00:02:37.139 of Antares is M4, a dense globular cluster that 00:02:37.139 --> 00:02:40.960 looks like a fuzzy star in binoculars. Right 00:02:40.960 --> 00:02:44.659 next door to Scorpius is Sagittarius, home to 00:02:44.659 --> 00:02:48.319 the famous teapot asterism. If you can trace 00:02:48.319 --> 00:02:52.120 the teapot shape, imagine steam rising from its 00:02:52.120 --> 00:02:56.060 spout. That glowing steam is actually the densest 00:02:56.060 --> 00:02:59.080 part of the Milky Way, and it's pointing straight 00:02:59.080 --> 00:03:02.580 toward the galactic core. Now, you can't see 00:03:02.580 --> 00:03:05.240 the center of the galaxy directly. It's hidden 00:03:05.240 --> 00:03:08.699 behind gas and dust. But you can look in the 00:03:08.699 --> 00:03:11.840 exact direction of it, which is kind of amazing. 00:03:12.400 --> 00:03:16.560 And right there, about 26 ,000 light years away, 00:03:16.919 --> 00:03:21.500 lies Sagittarius A, a supermassive black hole 00:03:21.500 --> 00:03:25.979 anchoring the Milky Way's spiral arms. The area 00:03:25.979 --> 00:03:29.500 around it is absolutely loaded with deep sky 00:03:29.500 --> 00:03:34.330 gems. There's M8, the Lagoon Nebula, a bright 00:03:34.330 --> 00:03:38.870 stellar nursery. M20, the Trifid Nebula, is a 00:03:38.870 --> 00:03:42.629 beautiful mix of newly born stars and dark dust. 00:03:43.590 --> 00:03:47.469 Also check out M22, one of the best globular 00:03:47.469 --> 00:03:51.030 clusters in the sky, and also easy to spot with 00:03:51.030 --> 00:03:54.539 binoculars. Even to the naked eye under dark 00:03:54.539 --> 00:03:57.340 skies, this part of the Milky Way looks puffier, 00:03:57.680 --> 00:04:00.699 brighter, and deeper. It's like the galaxy is 00:04:00.699 --> 00:04:04.900 exhaling. And of course, the summer triangle 00:04:04.900 --> 00:04:08.400 is rising. High in the east, later in the evening, 00:04:08.580 --> 00:04:11.439 you'll see three bright stars forming a giant 00:04:11.439 --> 00:04:16.790 triangle. Vega, Altair, and Deneb. The Triangle 00:04:16.790 --> 00:04:19.430 is up for most of the night and offers a gateway 00:04:19.430 --> 00:04:23.470 to other fun targets like the Ring Nebula M57 00:04:23.470 --> 00:04:28.069 in Lyra and the North America Nebula near Deneb. 00:04:35.810 --> 00:04:39.230 Have you ever seen the sun set perfectly between 00:04:39.230 --> 00:04:42.230 city buildings like it was aiming right down 00:04:42.230 --> 00:04:45.709 the street? If you were in New York City last 00:04:45.709 --> 00:04:48.769 week, you might have caught Manhattan Hinge. 00:04:49.550 --> 00:04:51.889 That's when the sun lines up just right with 00:04:51.889 --> 00:04:55.370 Manhattan's grid, beaming down the east -west 00:04:55.370 --> 00:04:59.189 streets like a spotlight. But if you missed it, 00:04:59.209 --> 00:05:01.769 and if you happen to be in New York City in a 00:05:01.769 --> 00:05:04.350 few weeks, you'll get another shot to see it. 00:05:05.310 --> 00:05:07.949 The next Manhattan Hinge is happening around 00:05:07.949 --> 00:05:11.420 July the 12th and 13th. And if you're nowhere 00:05:11.420 --> 00:05:14.839 near Manhattan, stick around because your city 00:05:14.839 --> 00:05:17.800 might have its own version of this urban sky 00:05:17.800 --> 00:05:22.160 alignment. So what exactly is Manhattan Hinge? 00:05:22.720 --> 00:05:25.300 It's a twice -a -year event when the setting 00:05:25.300 --> 00:05:29.300 sun aligns with Manhattan's slightly tilted street 00:05:29.300 --> 00:05:33.240 grid. The result is, for a few minutes, the sun 00:05:33.240 --> 00:05:35.959 drops directly between the buildings, lighting 00:05:35.959 --> 00:05:39.800 up the avenues in a perfect glowing frame. New 00:05:39.800 --> 00:05:43.220 York's street grid is rotated about 29 degrees 00:05:43.220 --> 00:05:47.500 off True East and West, so this solar alignment 00:05:47.500 --> 00:05:50.920 happens only when the Sun's path intersects that 00:05:50.920 --> 00:05:54.920 angle, once in late May and again in mid -July. 00:05:55.680 --> 00:05:59.259 Some top spots to view it include 42nd Street, 00:05:59.759 --> 00:06:04.269 34th Street, and 14th Street. The phenomenon 00:06:04.269 --> 00:06:07.370 was dubbed Manhattan Hinge by science educator 00:06:07.370 --> 00:06:10.769 Neil deGrasse Tyson, and that of course is a 00:06:10.769 --> 00:06:14.509 reference to Stonehenge, the prehistoric stone 00:06:14.509 --> 00:06:17.569 circle in England that forms a cosmic calendar, 00:06:18.069 --> 00:06:21.470 and it aligns with the summer solstice sunrise 00:06:21.470 --> 00:06:26.629 and winter solstice sunset. Stonehenge has modern 00:06:26.629 --> 00:06:29.689 pagans who gather to experience the solar phenomenon, 00:06:30.110 --> 00:06:34.439 while New York City has, well, taxis. New York 00:06:34.439 --> 00:06:37.079 isn't the only place that gets this light show. 00:06:37.519 --> 00:06:41.600 Cities like Chicago, Toronto, Montreal, Philadelphia, 00:06:42.000 --> 00:06:45.839 and Salt Lake City all experience similar events, 00:06:46.240 --> 00:06:49.600 sometimes at sunset, sometimes at sunrise, depending 00:06:49.600 --> 00:06:53.519 on their grid orientation. For example, Chicago 00:06:53.519 --> 00:06:57.519 has Chicago Hinge near the spring and fall equinoxes 00:06:57.519 --> 00:07:01.439 because its street grid runs true east to west. 00:07:02.179 --> 00:07:05.180 So, how can you tell if your city has a hinge 00:07:05.180 --> 00:07:08.399 of its own? This is where a little digital astronomy 00:07:08.399 --> 00:07:11.740 comes in handy. There's a great tool called the 00:07:11.740 --> 00:07:15.300 photographer's ephemeris, and it lets you map 00:07:15.300 --> 00:07:18.720 the sun's path for any date and place on Earth. 00:07:19.480 --> 00:07:22.680 You can overlay that info onto your city's street 00:07:22.680 --> 00:07:26.040 grid and figure out when the sun will align with 00:07:26.040 --> 00:07:29.259 your favorite thoroughfare. It's super useful 00:07:29.259 --> 00:07:32.100 if you're chasing that perfect golden hour photo 00:07:32.100 --> 00:07:35.220 or just want to know when your city might surprise 00:07:35.220 --> 00:07:38.779 you with a solar corridor. So maybe there's a 00:07:38.779 --> 00:07:48.639 hinge waiting just a few blocks from you. Let's 00:07:48.639 --> 00:07:51.819 shift gears a little from stargazing with your 00:07:51.819 --> 00:07:55.500 eyes to something that's mostly invisible but 00:07:55.500 --> 00:07:59.120 still incredibly important. Tonight, I want to 00:07:59.120 --> 00:08:01.420 take you behind the scenes of the solar system 00:08:01.420 --> 00:08:04.579 into the hidden architecture that holds things 00:08:04.579 --> 00:08:08.939 steady in space. We're talking about the Lagrange 00:08:08.939 --> 00:08:12.600 points, those weird gravitational sweet spots 00:08:12.600 --> 00:08:16.160 that make spaceflight smarter, smoother, and 00:08:16.160 --> 00:08:19.970 in some cases, just a little bit spooky. If you've 00:08:19.970 --> 00:08:22.689 never heard of them before, Lagrange points, 00:08:23.050 --> 00:08:26.709 sometimes just called L points, are specific 00:08:26.709 --> 00:08:29.910 spots in space where the gravity of two large 00:08:29.910 --> 00:08:32.889 objects, like the Earth and the Sun, balances 00:08:32.889 --> 00:08:36.850 out just right. So right, in fact, that a third, 00:08:36.990 --> 00:08:40.490 much smaller object, like a satellite, can just 00:08:40.490 --> 00:08:44.049 sort of hang out there, using no thrusters or 00:08:44.049 --> 00:08:47.379 any fuel. It just drifts along in harmony with 00:08:47.379 --> 00:08:51.779 the big cosmic players. So picture this, you've 00:08:51.779 --> 00:08:54.860 got the Earth orbiting the Sun, and both of them 00:08:54.860 --> 00:08:57.440 are tugging on a satellite with their combined 00:08:57.440 --> 00:09:00.840 gravity. Normally, that would yank the satellite 00:09:00.840 --> 00:09:04.379 around unpredictably, but at a Lagrange point, 00:09:04.759 --> 00:09:07.539 the gravitational pulls and the orbital motion 00:09:07.539 --> 00:09:11.639 all sync up perfectly, like a cosmic dance step 00:09:11.639 --> 00:09:14.340 where the satellite always lands right on the 00:09:14.340 --> 00:09:17.370 beat. There are five of these Lagrange points 00:09:17.370 --> 00:09:20.789 in any two -body system. Let's stick with the 00:09:20.789 --> 00:09:25.370 big show for now, the Earth -Sun system. L1 is 00:09:25.370 --> 00:09:29.730 for sun watchers. The first Lagrange point, L1, 00:09:29.870 --> 00:09:33.049 sits directly between Earth and the Sun. It's 00:09:33.049 --> 00:09:36.009 about a million miles from Earth, closer to the 00:09:36.009 --> 00:09:39.090 Sun than we are, but locked in Earth's orbital 00:09:39.090 --> 00:09:42.919 path. This is where we park solar observatories 00:09:42.919 --> 00:09:46.039 like SOHO and the Discover spacecraft because 00:09:46.039 --> 00:09:49.559 L1 gives them an uninterrupted view of the Sun, 00:09:50.059 --> 00:09:53.399 which is perfect for studying solar flares, sunspots, 00:09:53.559 --> 00:09:56.000 and space weather that can affect satellites 00:09:56.000 --> 00:09:59.559 and even power grids down here on Earth. It's 00:09:59.559 --> 00:10:02.600 the front row seat for solar drama, and it's 00:10:02.600 --> 00:10:08.169 always in the light. Now L2 is a nice place for 00:10:08.169 --> 00:10:12.450 deep space stargazers. L2 is located about a 00:10:12.450 --> 00:10:15.129 million miles away from Earth, but on the far 00:10:15.129 --> 00:10:18.690 side away from the Sun. This spot is special 00:10:18.690 --> 00:10:21.429 because it allows telescopes to stay in Earth's 00:10:21.429 --> 00:10:24.889 shadow, with the Sun, Earth, and Moon all behind 00:10:24.889 --> 00:10:28.590 them. That makes it incredibly cold and dark, 00:10:28.929 --> 00:10:31.629 just what you want for observing faint galaxies 00:10:31.629 --> 00:10:35.720 and distant stars. This is where the James Webb 00:10:35.720 --> 00:10:39.159 Space Telescope lives. Its mirrors and instruments 00:10:39.159 --> 00:10:41.779 are designed to pick up the faintest heat signatures 00:10:41.779 --> 00:10:45.240 in the universe, so it needs that cold, quiet 00:10:45.240 --> 00:10:48.960 neighborhood. Think of L2 as the astronomer's 00:10:48.960 --> 00:10:54.059 porch, but with the light turned off. L3 is sometimes 00:10:54.059 --> 00:10:58.220 called the phantom point. L3 sits on the far 00:10:58.220 --> 00:11:01.529 side of the Sun, directly opposite Earth. It's 00:11:01.529 --> 00:11:04.570 always hidden from our view. You can't see it 00:11:04.570 --> 00:11:07.190 from here, and that's what's given rise to all 00:11:07.190 --> 00:11:10.769 kinds of fun science fiction ideas like secret 00:11:10.769 --> 00:11:14.590 planets, alien outposts, or even doppelganger 00:11:14.590 --> 00:11:18.450 Earths hiding in the blind spot. But in real 00:11:18.450 --> 00:11:22.169 life, L3 isn't all that stable. If you tried 00:11:22.169 --> 00:11:24.570 to park a satellite there, it would eventually 00:11:24.570 --> 00:11:29.509 drift away. Think of L4 and L5 as the cosmic 00:11:29.509 --> 00:11:33.590 rest stops. These points form the tips of an 00:11:33.590 --> 00:11:36.570 equilateral triangle with the Earth and the Sun. 00:11:37.169 --> 00:11:40.250 That means they lead and trail Earth in its orbit 00:11:40.250 --> 00:11:45.509 about 60 degrees ahead of and behind. L4 and 00:11:45.509 --> 00:11:49.690 L5 are really stable. Objects placed there tend 00:11:49.690 --> 00:11:52.210 to stay put even if they get nudged a little. 00:11:52.490 --> 00:11:55.950 They often collect space debris, dust clouds, 00:11:56.269 --> 00:11:59.809 and even asteroids. Jupiter, for example, has 00:11:59.809 --> 00:12:03.169 thousands of asteroids camped out at its L4 and 00:12:03.169 --> 00:12:07.289 L5 points. Earth has a few too, though they're 00:12:07.289 --> 00:12:10.970 much smaller and harder to spot. Some scientists 00:12:10.970 --> 00:12:14.629 even speculate that alien probes, if they existed, 00:12:15.110 --> 00:12:19.830 would choose L4 or L5 as a parking spot. They're 00:12:19.830 --> 00:12:23.169 hidden, stable, and offer a great long -term 00:12:23.169 --> 00:12:26.909 view of Earth. So what makes these places so 00:12:26.909 --> 00:12:30.269 valuable? For one, they reduce the energy needed 00:12:30.269 --> 00:12:34.289 to keep spacecraft in a fixed position. That 00:12:34.289 --> 00:12:37.850 means less fuel, longer missions, and more stable 00:12:37.850 --> 00:12:41.289 instruments. And for future space infrastructure, 00:12:41.730 --> 00:12:44.570 things like observatories, solar power stations, 00:12:44.629 --> 00:12:48.389 or even planetary defense systems, Lagrange points 00:12:48.389 --> 00:12:52.090 offer premium real estate. They also give us 00:12:52.090 --> 00:12:54.730 strategic vantage points, whether we're monitoring 00:12:54.730 --> 00:12:58.009 solar storms, peering into deep space, or preparing 00:12:58.009 --> 00:13:01.830 for interplanetary travel. These points let us 00:13:01.830 --> 00:13:04.690 place our tools exactly where they'll be most 00:13:04.690 --> 00:13:07.460 effective. So the next time you hear about a 00:13:07.460 --> 00:13:10.360 new space telescope or satellite mission, listen 00:13:10.360 --> 00:13:13.100 closely and there's a good chance it's heading 00:13:13.100 --> 00:13:16.240 for one of these gravitational sweet spots. For 00:13:16.240 --> 00:13:19.940 the math of motion and the poetry of space come 00:13:19.940 --> 00:13:28.059 together just right. If the stars spoke to you 00:13:28.059 --> 00:13:30.639 this week or if a question's been on your mind, 00:13:30.720 --> 00:13:34.549 I'd love to hear it. Visit our website, StarTrails 00:13:34.549 --> 00:13:38.350 .Show, where you can contact me and explore past 00:13:38.350 --> 00:13:42.110 episodes. Be sure to follow us on Mastodon, Blue 00:13:42.110 --> 00:13:45.389 Sky, and YouTube. Links are in the show notes. 00:13:46.210 --> 00:13:48.889 Until we meet again beneath the stars, clear 00:13:48.889 --> 00:13:49.730 skies everyone.