WEBVTT 00:00:07.719 --> 00:00:10.380 Howdy Star Gazers and welcome to this episode 00:00:10.380 --> 00:00:13.500 of Star Trails. My name is Drew, and I'll be 00:00:13.500 --> 00:00:16.339 your guide to the night sky for the week of January 00:00:16.339 --> 00:00:21.059 the 18th through the 24th. This week we'll continue 00:00:21.059 --> 00:00:24.359 in our series aimed at new astronomers by exploring 00:00:24.359 --> 00:00:27.359 how the universe moves, it's stranger than you 00:00:27.359 --> 00:00:30.179 think, and we'll cover everything from the backward 00:00:30.179 --> 00:00:33.039 motion of planets to the wobble that lets us 00:00:33.039 --> 00:00:35.579 glimpse a bit of the far side of the moon from 00:00:35.579 --> 00:00:39.000 time to time. Later in the show we'll take a 00:00:39.000 --> 00:00:41.060 look at what you can expect to see in the night 00:00:41.060 --> 00:00:43.820 sky this week, and we'll officially kick off 00:00:43.820 --> 00:00:47.369 our Star Trails book club. Whether you're tuning 00:00:47.369 --> 00:00:50.189 in from the backyard or the balcony, I'm glad 00:00:50.189 --> 00:00:52.710 you're here. So grab a comfortable spot under 00:00:52.710 --> 00:01:01.270 the night sky and let's get started. Step outside 00:01:01.270 --> 00:01:05.090 on a clear night. Let the air settle. No wind, 00:01:05.409 --> 00:01:09.489 no sound, no sense of movement at all. You're 00:01:09.489 --> 00:01:13.849 standing perfectly still. But you're not. Because 00:01:13.849 --> 00:01:17.319 right now, at this second, You're moving at about 00:01:17.319 --> 00:01:20.980 a thousand miles per hour, because Earth is spinning. 00:01:21.680 --> 00:01:24.280 If you're anywhere near the equator, you're riding 00:01:24.280 --> 00:01:28.920 the fastest part of that spin. At the same time, 00:01:29.040 --> 00:01:32.519 Earth is racing around the sun at roughly 67 00:01:32.519 --> 00:01:36.900 ,000 miles per hour. That's one full orbit every 00:01:36.900 --> 00:01:40.620 year. An enormous curve traced through space 00:01:40.620 --> 00:01:44.540 that you never feel. And the sun itself, the 00:01:44.540 --> 00:01:47.819 anchor of our entire solar system, is orbiting 00:01:47.819 --> 00:01:50.659 the center of the Milky Way at around half a 00:01:50.659 --> 00:01:54.159 million miles per hour, carrying Earth, the moon, 00:01:54.340 --> 00:01:57.959 and every planet along for the ride. And even 00:01:57.959 --> 00:02:01.340 that isn't the end of it. The Milky Way itself 00:02:01.340 --> 00:02:04.280 is moving through intergalactic space at well 00:02:04.280 --> 00:02:08.199 over a million miles per hour, drawn by the gravity 00:02:08.199 --> 00:02:12.460 of nearby galaxy groups. So, depending on how 00:02:12.460 --> 00:02:15.139 you measure it, you can easily say you're moving 00:02:15.139 --> 00:02:18.120 at more than a million miles per hour. You're 00:02:18.120 --> 00:02:21.280 making Formula One champions like Lewis Hamilton 00:02:21.280 --> 00:02:25.219 and Max Verstappen look slow, just by standing 00:02:25.219 --> 00:02:29.800 still. Of course, it's all relative, because 00:02:29.800 --> 00:02:33.259 everything in the universe is moving. The universe 00:02:33.259 --> 00:02:37.560 doesn't feel fast, but it is. And once you understand 00:02:37.560 --> 00:02:40.539 that, the movement of the night sky starts to 00:02:40.539 --> 00:02:44.340 make a lot more sense. So let's start with the 00:02:44.340 --> 00:02:47.840 motion you can actually see. Over the course 00:02:47.840 --> 00:02:51.400 of an evening, stars rise in the east, arc across 00:02:51.400 --> 00:02:55.819 the sky, and set in the west. Orion climbs higher. 00:02:56.340 --> 00:02:59.520 Sirius flashes near the horizon. Everything seems 00:02:59.520 --> 00:03:03.599 to drift westward together. That isn't the sky 00:03:03.599 --> 00:03:07.169 moving, it's the earth turning. We're standing 00:03:07.169 --> 00:03:10.550 on a rotating planet, and the sky is fixed far 00:03:10.550 --> 00:03:14.349 beyond us. As Earth spins, our view changes. 00:03:15.150 --> 00:03:17.750 If you sit outside long enough, you can actually 00:03:17.750 --> 00:03:21.490 feel this motion intellectually. The stars aren't 00:03:21.490 --> 00:03:24.229 sliding across the sky. You're being carried 00:03:24.229 --> 00:03:28.090 beneath them. This is the most immediate motion 00:03:28.090 --> 00:03:31.129 of the universe, and it's the one backyard astronomers 00:03:31.129 --> 00:03:34.710 learn first. It's also the reason time matters 00:03:34.710 --> 00:03:38.379 when you observe. Where something is at 8 p .m. 00:03:38.560 --> 00:03:42.500 is not where it will be at midnight. We say this 00:03:42.500 --> 00:03:46.460 frequently, the sky is a clock and it never stops 00:03:46.460 --> 00:03:49.939 ticking. While the motion of the stars may seem 00:03:49.939 --> 00:03:52.759 imperceptible at a glance, if you've ever used 00:03:52.759 --> 00:03:55.460 a telescope, you've seen the motion firsthand. 00:03:56.139 --> 00:03:58.360 While you're magnifying the view of a planet, 00:03:58.539 --> 00:04:01.740 such as Jupiter, you're also magnifying the motion 00:04:01.740 --> 00:04:04.939 of the sky. If you're using a telescope without 00:04:04.939 --> 00:04:07.719 a motor drive, you've no doubt been frustrated 00:04:07.719 --> 00:04:10.500 as you've watched your target planet speed out 00:04:10.500 --> 00:04:20.259 of view, forcing you to reframe it. Even the 00:04:20.259 --> 00:04:23.420 light from stars has to account for our motion. 00:04:24.060 --> 00:04:27.759 As Earth moves through space, the direction starlight 00:04:27.759 --> 00:04:30.759 appears to come from is shifted ever so slightly 00:04:30.759 --> 00:04:34.220 in the direction we're traveling. This effect 00:04:34.220 --> 00:04:37.879 is called aberration of starlight, and it's subtle, 00:04:38.040 --> 00:04:42.240 only a tiny fraction of a degree. A useful way 00:04:42.240 --> 00:04:45.500 to imagine it is walking through rain. Even if 00:04:45.500 --> 00:04:48.279 the rain is falling straight down, you tilt your 00:04:48.279 --> 00:04:52.319 umbrella forward because you are moving. Starlight 00:04:52.319 --> 00:04:55.879 works the same way. The stars aren't changing 00:04:55.879 --> 00:04:58.759 position, but because Earth is racing along its 00:04:58.759 --> 00:05:01.959 orbit, the light reaches us at a slight angle. 00:05:03.500 --> 00:05:06.459 What's remarkable is that this effect was measured 00:05:06.459 --> 00:05:10.160 centuries ago, long before spacecraft or satellites. 00:05:10.720 --> 00:05:13.439 Astronomers noticed that star positions shifted 00:05:13.439 --> 00:05:16.300 in a way that could only be explained if Earth 00:05:16.300 --> 00:05:20.399 was moving through space. In other words, the 00:05:20.399 --> 00:05:23.459 sky isn't just telling us where things are, it's 00:05:23.459 --> 00:05:28.459 quietly revealing how fast we're going. If Earth's 00:05:28.459 --> 00:05:31.519 rotation explains the nightly motion, the moon 00:05:31.519 --> 00:05:35.579 introduces complication. The moon doesn't rise 00:05:35.579 --> 00:05:38.800 at the same time each night. It shifts eastward 00:05:38.800 --> 00:05:42.480 by about 13 degrees every day, which means it 00:05:42.480 --> 00:05:45.459 rises roughly 50 minutes later from one night 00:05:45.459 --> 00:05:48.660 to the next. That's why it sometimes appears 00:05:48.660 --> 00:05:51.399 in the evening sky, sometimes after midnight, 00:05:51.600 --> 00:05:56.790 and sometimes not at all. Its phases are orbital 00:05:56.790 --> 00:06:00.509 geometry. As the moon orbits Earth, we see different 00:06:00.509 --> 00:06:04.410 portions of its sunlit half. That slow, steady 00:06:04.410 --> 00:06:08.449 orbit shapes the rhythm of the month. And the 00:06:08.449 --> 00:06:11.389 moon's orbit isn't perfectly circular. When a 00:06:11.389 --> 00:06:14.189 full moon happens near its closest point to Earth, 00:06:14.610 --> 00:06:17.810 it appears slightly larger and brighter. A so 00:06:17.810 --> 00:06:21.139 -called supermoon. When it's farther away, it 00:06:21.139 --> 00:06:23.939 looks smaller and dimmer, and we call that a 00:06:23.939 --> 00:06:28.279 micro moon. One of the most common things people 00:06:28.279 --> 00:06:30.980 hear about the moon is that we always see the 00:06:30.980 --> 00:06:34.660 same face, as if the moon has chosen a side and 00:06:34.660 --> 00:06:38.199 stubbornly refuses to turn around. But what's 00:06:38.199 --> 00:06:41.319 actually happening is subtler and more elegant. 00:06:42.259 --> 00:06:45.879 The moon does rotate, it just rotates at exactly 00:06:45.879 --> 00:06:50.000 the same rate that it orbits Earth. This is called 00:06:50.000 --> 00:06:53.000 tidal locking, and it's the result of gravity 00:06:53.000 --> 00:06:56.860 acting over enormous stretches of time. Early 00:06:56.860 --> 00:06:59.740 in its history, the moon likely spun faster. 00:07:00.360 --> 00:07:03.779 Earth's gravity raised tides in the moon's interior, 00:07:04.100 --> 00:07:07.480 not ocean tides, but solid body distortions. 00:07:08.500 --> 00:07:11.899 Those tidal bulges created friction, and friction 00:07:11.899 --> 00:07:15.899 drains energy. Over millions of years, that process 00:07:15.899 --> 00:07:18.920 slowed the Moon's rotation until it reached a 00:07:18.920 --> 00:07:23.860 stable state, one rotation for every orbit. The 00:07:23.860 --> 00:07:27.579 result is synchronization. As the Moon goes once 00:07:27.579 --> 00:07:30.980 around Earth, it turns once on its axis. From 00:07:30.980 --> 00:07:33.860 our point of view, that means the same hemisphere 00:07:33.860 --> 00:07:38.699 always faces us. And it's worth pausing on a 00:07:38.699 --> 00:07:41.709 detail that often gets missed. Tidal locking 00:07:41.709 --> 00:07:45.009 doesn't mean the moon doesn't spin. If it didn't 00:07:45.009 --> 00:07:47.930 rotate at all, we would see every side over the 00:07:47.930 --> 00:07:50.970 course of a month. The fact that we don't is 00:07:50.970 --> 00:07:53.810 proof that it's rotating perfectly in step with 00:07:53.810 --> 00:07:57.550 its orbit. Even then, the story isn't perfectly 00:07:57.550 --> 00:08:01.089 tidy. Because the moon's orbit is slightly elliptical 00:08:01.089 --> 00:08:03.930 and tilted, its rotation speed doesn't match 00:08:03.930 --> 00:08:08.329 its orbital speed exactly at every point. That 00:08:08.329 --> 00:08:11.850 mismatch produces Libration, a gentle rocking 00:08:11.850 --> 00:08:14.449 that lets us glimpse a little beyond the Moon's 00:08:14.449 --> 00:08:17.889 edge over time. That's why across months we can 00:08:17.889 --> 00:08:21.310 see about 59 % of the Moon's surface, rather 00:08:21.310 --> 00:08:27.509 than the 50 you might expect. So the Moon keeps 00:08:27.509 --> 00:08:30.290 one face towards Earth, not because it's frozen 00:08:30.290 --> 00:08:33.009 in place, but because it's locked in a gravitational 00:08:33.009 --> 00:08:36.759 rhythm. rotating, orbiting, and wobbling just 00:08:36.759 --> 00:08:39.159 enough to remind careful observers that even 00:08:39.159 --> 00:08:42.200 the most familiar object in the night sky is 00:08:42.200 --> 00:08:47.639 still very much in motion. Now let's zoom out. 00:08:48.500 --> 00:08:52.399 Over weeks and months the entire night sky changes. 00:08:53.039 --> 00:08:56.299 Orion dominates winter evenings, but by late 00:08:56.299 --> 00:09:00.159 spring it slips away. Summer constellations take 00:09:00.159 --> 00:09:04.019 its place. By autumn, the sky feels unfamiliar 00:09:04.019 --> 00:09:08.720 again. The stars aren't leaving. We are. As Earth 00:09:08.720 --> 00:09:12.259 orbits the sun, our nighttime view points in 00:09:12.259 --> 00:09:14.320 different directions at different times of the 00:09:14.320 --> 00:09:18.299 year. The stars behind the sun in July are not 00:09:18.299 --> 00:09:22.000 the same stars behind it in January. Seasonal 00:09:22.000 --> 00:09:25.799 skies are a consequence of perspective, not disappearance. 00:09:26.320 --> 00:09:29.259 And once you see that pattern, the night sky 00:09:29.259 --> 00:09:31.960 stops feeling like a puzzle and starts feeling 00:09:31.960 --> 00:09:36.740 like a landscape. Some of the oddest behaviors 00:09:36.740 --> 00:09:40.860 come from relative motion. Planets, for example, 00:09:41.059 --> 00:09:43.759 usually drift eastward against the background 00:09:43.759 --> 00:09:47.919 stars. But every so often, they slow down, stop, 00:09:48.159 --> 00:09:52.100 and move backward for a time. This retrograde 00:09:52.100 --> 00:09:56.379 motion baffled astronomers for centuries. The 00:09:56.379 --> 00:09:59.559 planets aren't reversing course, we're just passing 00:09:59.559 --> 00:10:03.460 them. Earth moves faster on an inner track, like 00:10:03.460 --> 00:10:07.179 a car overtaking another on a highway. From our 00:10:07.179 --> 00:10:09.899 moving viewpoint, the slower planet appears to 00:10:09.899 --> 00:10:13.059 loop backward briefly before resuming its usual 00:10:13.059 --> 00:10:16.320 direction. It's simply a matter of perspective. 00:10:18.000 --> 00:10:20.620 Up until now, everything we've talked about happens 00:10:20.620 --> 00:10:25.000 on human time scales. Hours, days, months, and 00:10:25.000 --> 00:10:28.860 years. But the universe has slower motions too, 00:10:29.159 --> 00:10:34.519 much slower. Earth's axis isn't fixed. It wobbles, 00:10:34.779 --> 00:10:38.580 tracing a slow circle over about 26 ,000 years. 00:10:39.679 --> 00:10:43.059 This motion, called precession, means the identity 00:10:43.059 --> 00:10:46.679 of the North Star changes over time. Polaris 00:10:46.679 --> 00:10:50.240 is only temporarily special. In the distant past, 00:10:50.600 --> 00:10:53.830 other stars marked North. In the far future, 00:10:54.289 --> 00:10:58.649 different ones will again. Even Earth's axial 00:10:58.649 --> 00:11:02.269 wobble isn't perfectly smooth. On top of long 00:11:02.269 --> 00:11:05.649 -term precession is a smaller motion called nutation, 00:11:06.210 --> 00:11:09.210 a subtle nodding and jittering of Earth's axis 00:11:09.210 --> 00:11:12.389 caused mostly by the Moon's changing gravitational 00:11:12.389 --> 00:11:16.649 pull. As the Moon's orbit tilts and shifts, Earth 00:11:16.649 --> 00:11:19.710 responds with a gentle shimmy layered over its 00:11:19.710 --> 00:11:24.000 larger wobble. The key idea here is Earth doesn't 00:11:24.000 --> 00:11:28.919 move in idealized curves, and it never has. Even 00:11:28.919 --> 00:11:33.039 the Sun isn't standing still. Earth doesn't orbit 00:11:33.039 --> 00:11:37.320 a perfectly fixed Sun. Instead, both Earth and 00:11:37.320 --> 00:11:40.299 the Sun orbit a shared center of mass called 00:11:40.299 --> 00:11:43.840 a barycenter, a point in space determined by 00:11:43.840 --> 00:11:48.929 their combined gravity. Most of the time, that 00:11:48.929 --> 00:11:52.110 point lies just outside the sun's surface, but 00:11:52.110 --> 00:11:56.409 it shifts constantly as planets move. Add in 00:11:56.409 --> 00:11:59.330 massive worlds like Jupiter and Saturn, and the 00:11:59.330 --> 00:12:02.690 sun begins to wobble, subtly but measurably. 00:12:03.450 --> 00:12:06.129 This means the solar system doesn't revolve around 00:12:06.129 --> 00:12:09.490 a motionless center. Everything is responding 00:12:09.490 --> 00:12:13.789 to everything else. All the stars we see are 00:12:13.789 --> 00:12:17.789 also moving. They orbit the galaxy. drift relative 00:12:17.789 --> 00:12:21.149 to one another, and slowly change position against 00:12:21.149 --> 00:12:25.230 the background sky. This is called proper motion, 00:12:25.629 --> 00:12:28.169 and while it's almost invisible over a single 00:12:28.169 --> 00:12:31.409 lifetime, it becomes obvious across centuries 00:12:31.409 --> 00:12:36.710 and millennia. If you want proof that stars themselves 00:12:36.710 --> 00:12:40.070 are moving and not just in some abstract, academic 00:12:40.070 --> 00:12:43.960 way, There's a quiet little red star in the constellation 00:12:43.960 --> 00:12:47.039 Ophiuchus that tells the story better than any 00:12:47.039 --> 00:12:51.159 diagram. It's called Bernard's star, and it holds 00:12:51.159 --> 00:12:54.519 a remarkable record. It has the fastest known 00:12:54.519 --> 00:13:01.120 proper motion of any star in the night sky. Bernard's 00:13:01.120 --> 00:13:04.279 star drifts across the sky at about 10 arc seconds 00:13:04.279 --> 00:13:07.940 per year. That doesn't sound like much, and visually 00:13:07.940 --> 00:13:11.559 it isn't. But over a human lifetime, its position 00:13:11.559 --> 00:13:14.360 shifts enough to be measured easily with modest 00:13:14.360 --> 00:13:18.419 equipment. Over a few centuries, it noticeably 00:13:18.419 --> 00:13:20.919 changes where it sits relative to neighboring 00:13:20.919 --> 00:13:24.720 stars. Given enough time, it will wander completely 00:13:24.720 --> 00:13:27.639 out of the familiar star patterns we use today. 00:13:29.740 --> 00:13:32.519 What makes this especially striking is why it's 00:13:32.519 --> 00:13:36.179 happening. Bernard's star isn't unusually fast 00:13:36.179 --> 00:13:40.360 in an absolute sense, it's just close, only about 00:13:40.360 --> 00:13:44.220 six light years away. Its proximity makes its 00:13:44.220 --> 00:13:48.080 motion obvious. The stars are not fixed points, 00:13:48.340 --> 00:13:50.700 they're travelers, and we're watching them in 00:13:50.700 --> 00:13:54.259 the middle of their journeys. Constellations 00:13:54.259 --> 00:13:57.539 feel eternal, but they aren't. They're temporary 00:13:57.539 --> 00:14:00.620 patterns, snapshots taken during a brief moment 00:14:00.620 --> 00:14:03.519 when star motions happen to line up in a familiar 00:14:03.519 --> 00:14:08.019 way. The sky we know is not the sky our distant 00:14:08.019 --> 00:14:12.200 descendants will see. All of this motion, spins, 00:14:12.580 --> 00:14:15.519 orbits, wobbles, drifts, can feel overwhelming 00:14:15.519 --> 00:14:18.100 when you list it out, but here's the quiet truth 00:14:18.100 --> 00:14:22.299 at the center of it all. The sky looks stable 00:14:22.299 --> 00:14:25.440 because we're moving with it. We share Earth's 00:14:25.440 --> 00:14:28.580 rotation. We share the Sun's galactic orbit. 00:14:28.980 --> 00:14:32.600 We share our local neighborhood of stars. And 00:14:32.600 --> 00:14:36.039 even at the largest scales, motion never disappears. 00:14:37.059 --> 00:14:40.879 The Milky Way is not a rigid disk frozen in space. 00:14:41.100 --> 00:14:43.879 It flexes and stretches under the gravitational 00:14:43.879 --> 00:14:47.559 influence of nearby galaxies. especially the 00:14:47.559 --> 00:14:50.200 Andromeda galaxy, which is slowly approaching 00:14:50.200 --> 00:14:55.240 us. These galactic tides gently reshape stellar 00:14:55.240 --> 00:14:58.860 orbits over hundreds of millions of years. The 00:14:58.860 --> 00:15:02.039 same gravity that raises tides on Earth and locks 00:15:02.039 --> 00:15:05.820 the moon to our planet also sculpts galaxies. 00:15:07.399 --> 00:15:10.639 There's one last wrinkle in this motion. When 00:15:10.639 --> 00:15:13.200 you look at the sky, you're never seeing things 00:15:13.200 --> 00:15:17.429 as they are right now. Moonlight is about one 00:15:17.429 --> 00:15:21.350 second old. Sunlight left eight minutes ago. 00:15:21.850 --> 00:15:25.570 The stars of Orion shine from hundreds or thousands 00:15:25.570 --> 00:15:28.950 of years in the past. So all the motion we're 00:15:28.950 --> 00:15:31.950 talking about, you're watching it slightly delayed, 00:15:32.450 --> 00:15:35.169 stitched together from different moments in time. 00:15:36.269 --> 00:15:38.570 Astronomy isn't just the study of where things 00:15:38.570 --> 00:15:41.269 are, it's the study of where things were and 00:15:41.269 --> 00:15:44.129 how their motion reaches us across distance. 00:15:44.779 --> 00:15:48.480 The night sky isn't still, and once you understand 00:15:48.480 --> 00:15:51.460 that, every observation starts to feel less like 00:15:51.460 --> 00:16:03.440 confusion and more like choreography. After a 00:16:03.440 --> 00:16:05.840 quick break, we'll return with this week's night 00:16:05.840 --> 00:16:08.799 sky report and the first reading assignment for 00:16:08.799 --> 00:16:25.980 our book club. Stay with us. Welcome back! Tonight 00:16:25.980 --> 00:16:28.679 and over the coming week, a nearly absent moon 00:16:28.679 --> 00:16:31.240 will make for some of the best dark sky observing 00:16:31.240 --> 00:16:34.940 many of us get all winter. We reach New Moon 00:16:34.940 --> 00:16:37.320 tonight, which means the moon will be nearly 00:16:37.320 --> 00:16:40.059 invisible in the sky for several evenings around 00:16:40.059 --> 00:16:43.820 this date. With virtually no lunar glow to wash 00:16:43.820 --> 00:16:46.940 out faint objects, this is an ideal time to explore 00:16:46.940 --> 00:16:50.919 galaxies, nebula, and star clusters with binoculars 00:16:50.919 --> 00:16:54.419 or a telescope. With the moon out of the way 00:16:54.419 --> 00:16:56.980 early in the week, the planet Jupiter continues 00:16:56.980 --> 00:17:00.419 to dominate the night sky. Earlier in January, 00:17:00.600 --> 00:17:03.519 Jupiter reached opposition, meaning Earth passed 00:17:03.519 --> 00:17:06.579 directly between it and the Sun, and it will 00:17:06.579 --> 00:17:09.380 remain bright and prominent through late January. 00:17:10.099 --> 00:17:13.680 The gas giant rises around sunset and stays visible 00:17:13.680 --> 00:17:16.799 all night. Climbing into the south and shining 00:17:16.799 --> 00:17:20.019 is one of the brightest objects in the sky. Even 00:17:20.019 --> 00:17:22.740 small telescopes and good binoculars can reveal 00:17:22.740 --> 00:17:26.319 its four largest moons, and under stable seeing, 00:17:26.839 --> 00:17:31.019 hints of cloud bands on its disk. Not far behind 00:17:31.019 --> 00:17:34.079 Jupiter in the evening sky is Saturn, visible 00:17:34.079 --> 00:17:37.740 after sunset in the southwest. Through a small 00:17:37.740 --> 00:17:40.920 telescope, Saturn's rings continue to be a delightful 00:17:40.920 --> 00:17:43.599 sight, though it will be lower in the sky than 00:17:43.599 --> 00:17:48.150 Jupiter. On January 23, an attractive pairing 00:17:48.150 --> 00:17:51.650 awaits observers. The thin, waxing crescent moon 00:17:51.650 --> 00:17:55.049 will appear close to Saturn and Neptune in the 00:17:55.049 --> 00:17:59.769 western sky after sunset. Saturn is, of course, 00:17:59.829 --> 00:18:02.910 bright enough to see with the unaided eye, and 00:18:02.910 --> 00:18:05.690 Neptune, much fainter, can be pulled out with 00:18:05.690 --> 00:18:08.210 binoculars or a telescope if you know where to 00:18:08.210 --> 00:18:12.390 look. An app like Stellarium can help you locate 00:18:12.390 --> 00:18:15.700 it precisely. This grouping makes a nice target 00:18:15.700 --> 00:18:19.180 for early evening observation as the moon's crescent 00:18:19.180 --> 00:18:23.359 returns. This week also offers the chance to 00:18:23.359 --> 00:18:26.819 revisit some deep sky favorites. The Beehive 00:18:26.819 --> 00:18:29.799 Cluster in Cancer is well placed in the eastern 00:18:29.799 --> 00:18:34.259 sky after dusk. This open cluster, also cataloged 00:18:34.259 --> 00:18:38.359 as Messier 44, is a beautiful sight in binoculars 00:18:38.359 --> 00:18:41.940 or a wide field telescope. appearing as a misty 00:18:41.940 --> 00:18:45.940 patch of dozens of stars. Also this week, if 00:18:45.940 --> 00:18:48.720 you're using telescopes with tracking or a good 00:18:48.720 --> 00:18:51.759 star chart, you can enjoy fainter wanderers. 00:18:52.240 --> 00:18:55.039 Uranus remains a binocular object tucked near 00:18:55.039 --> 00:18:58.059 the Pleiades cluster, and Neptune will be easier 00:18:58.059 --> 00:19:00.720 to spot during the Moon -Saturn close approach 00:19:00.720 --> 00:19:04.180 on the 23rd, though both require optical aid 00:19:04.180 --> 00:19:07.880 and some patience. Finally, take a moment to 00:19:07.880 --> 00:19:10.720 step back from specific targets and enjoy the 00:19:10.720 --> 00:19:13.680 winter Milky Way sprawling across the sky from 00:19:13.680 --> 00:19:17.839 Orion through Gemini and into Auriga and Perseus. 00:19:18.339 --> 00:19:20.980 With few nights this dark all month, the winter 00:19:20.980 --> 00:19:23.740 constellations and the rich patches of interstellar 00:19:23.740 --> 00:19:26.720 dust and star -birth regions around them are 00:19:26.720 --> 00:19:29.460 especially satisfying even through binoculars. 00:19:30.850 --> 00:19:34.349 That's a snapshot of what's up this week. Bundle 00:19:34.349 --> 00:19:37.170 up, step outside early in the evening, and let 00:19:37.170 --> 00:19:40.369 your eyes adjust. The dark skies this week are 00:19:40.369 --> 00:19:50.809 a gift. Okay folks, the Star Trails book club 00:19:50.809 --> 00:19:54.009 is finally happening. If you want to follow along, 00:19:54.230 --> 00:19:56.910 you're going to need a copy of Night Watch by 00:19:56.910 --> 00:20:00.019 Terrence Dickinson. Make sure you get the 5th 00:20:00.019 --> 00:20:02.460 edition for the most up -to -date information, 00:20:02.900 --> 00:20:05.519 although I'm reading the 4th edition, which is 00:20:05.519 --> 00:20:09.220 accurate to 2025. I don't think the stars on 00:20:09.220 --> 00:20:11.559 the included charts will have moved that much 00:20:11.559 --> 00:20:15.380 to make a difference. In our first show in February, 00:20:15.599 --> 00:20:18.019 two weeks from now, I'm going to talk about my 00:20:18.019 --> 00:20:20.839 favorite portions of the first three chapters. 00:20:21.660 --> 00:20:24.920 Chapter 1, Discovering the Cosmos, is a broad 00:20:24.920 --> 00:20:29.279 survey of the goals of the book. Chapter 2, The 00:20:29.279 --> 00:20:33.119 Universe in 11 Steps, sets up a fascinating discussion 00:20:33.119 --> 00:20:36.720 on the scale of the universe. And Chapter 3, 00:20:37.059 --> 00:20:40.099 Backyard Astronomy, really matches up well with 00:20:40.099 --> 00:20:42.859 the Star Trails philosophy, and it's full of 00:20:42.859 --> 00:20:46.619 useful tips for navigating the sky. I'll offer 00:20:46.619 --> 00:20:49.339 up my thoughts in more detail on these sections, 00:20:49.440 --> 00:20:51.960 and if you've read Nightwatch, I'd love to hear 00:20:51.960 --> 00:20:55.490 your reflections also. Feel free to comment over 00:20:55.490 --> 00:21:02.609 at StarTrails .Show. That's going to do it for 00:21:02.609 --> 00:21:05.150 this week. If you found this episode interesting, 00:21:05.309 --> 00:21:07.309 please share it with a friend who might enjoy 00:21:07.309 --> 00:21:10.089 it. The easiest way to do that is by sending 00:21:10.089 --> 00:21:14.569 folks to our website StarTrails .Show. And if 00:21:14.569 --> 00:21:16.789 you want to support the show, use the link on 00:21:16.789 --> 00:21:19.430 the site to buy me a coffee. It really helps. 00:21:20.589 --> 00:21:23.950 Be sure to follow Star Trails on Blue Sky and 00:21:23.950 --> 00:21:27.069 YouTube. Links are in the show notes. Until we 00:21:27.069 --> 00:21:30.230 meet again beneath the stars, clear skies everyone!