WEBVTT 00:00:07.580 --> 00:00:10.779 Howdy stargazers and welcome to Star Trails. 00:00:10.980 --> 00:00:13.679 I'm Drew and I'll be your guide to the night 00:00:13.679 --> 00:00:17.199 sky for the week of August the 31st to September 00:00:17.199 --> 00:00:21.179 6th. This is a week when the moon climbs from 00:00:21.179 --> 00:00:24.440 half -lit to nearly full, brightening each evening, 00:00:24.899 --> 00:00:28.660 and the outer planets take center stage. We'll 00:00:28.660 --> 00:00:32.359 also wander through a few oft -ignored constellations 00:00:32.359 --> 00:00:35.000 that hold some real treasures for small scopes 00:00:35.000 --> 00:00:38.240 and binoculars. Later in the show, we take a 00:00:38.240 --> 00:00:42.219 look at time from the watches worn on space missions, 00:00:42.820 --> 00:00:46.500 Martian days, and the time -warping science behind 00:00:46.500 --> 00:00:50.340 GPS satellites. Whether you're tuning in from 00:00:50.340 --> 00:00:53.539 the backyard, the balcony, or just your imagination, 00:00:53.899 --> 00:00:57.100 I'm glad you're here. So find a cozy spot, let 00:00:57.100 --> 00:00:59.880 your eyes adjust, and let's see what the sky 00:00:59.880 --> 00:01:04.140 holds for us this week. We start with our nearest 00:01:04.140 --> 00:01:07.140 neighbor. The moon reached first quarter in the 00:01:07.140 --> 00:01:10.840 early hours of Sunday morning and now it's waxing 00:01:10.840 --> 00:01:14.420 steadily through gibbous all week. By Saturday, 00:01:14.560 --> 00:01:17.540 it's a brilliant lantern nearly full with the 00:01:17.540 --> 00:01:21.319 official full moon arriving on Sunday the 7th. 00:01:21.500 --> 00:01:24.900 So your deep sky hunting windows shrink quickly. 00:01:25.260 --> 00:01:27.680 Favor the first half of the week if you want 00:01:27.680 --> 00:01:31.620 darker skies after midnight. Farther away, Saturn 00:01:31.620 --> 00:01:35.060 is a best bet right now. It's glowing in Pisces 00:01:35.060 --> 00:01:38.859 all evening, a bright golden ember. The rings 00:01:38.859 --> 00:01:41.599 are still at their thinnest in decades, edge 00:01:41.599 --> 00:01:45.079 -on and knife -like, but still a thrill in any 00:01:45.079 --> 00:01:48.620 telescope. Saturn reaches opposition later this 00:01:48.620 --> 00:01:52.799 month, so it will only get better. Neptune, also 00:01:52.799 --> 00:01:56.319 in Pisces, is nearby for late -night telescopic 00:01:56.319 --> 00:01:59.840 hunters. and Uranus comes up after midnight in 00:01:59.840 --> 00:02:04.239 Taurus. Mars is a low ember in the western twilight, 00:02:04.540 --> 00:02:08.060 hard to spot but technically present. Meanwhile, 00:02:08.280 --> 00:02:11.659 the mornings belong to Venus and Jupiter. Venus 00:02:11.659 --> 00:02:14.759 continues as the dazzling morning star while 00:02:14.759 --> 00:02:17.840 Jupiter rises earlier each night and sits near 00:02:17.840 --> 00:02:21.680 Gemini's bright twins, Castor and Pollux. A fine 00:02:21.680 --> 00:02:25.020 pairing to greet the dawn. If you're out in the 00:02:25.020 --> 00:02:28.300 early hours Monday morning, keep an eye on Auriga 00:02:28.300 --> 00:02:32.139 for the Aurigad meteor shower. It's usually faint, 00:02:32.240 --> 00:02:35.599 but has a history of surprise outbursts. And 00:02:35.599 --> 00:02:41.199 in the same part of the sky, Comet Lemmon C2025A6 00:02:41.199 --> 00:02:45.000 is sliding near Gemini. It's faint now, more 00:02:45.000 --> 00:02:48.439 a telescopic quarry, but worth noting as it brightens 00:02:48.439 --> 00:02:52.060 toward October. The brighter moon pushes us towards 00:02:52.060 --> 00:02:54.979 star clusters, doubles, and brighter objects 00:02:54.979 --> 00:02:58.740 that punch through moonlight. In Delphinus, the 00:02:58.740 --> 00:03:01.759 little diamond -shaped dolphin high in the southeast, 00:03:01.939 --> 00:03:06.780 you'll find two globular clusters, NGC 6934, 00:03:07.280 --> 00:03:14.139 a compact grainy ball, and NGC 7006, a distant 00:03:14.139 --> 00:03:17.740 halo globular so far away it appears as a mere 00:03:17.740 --> 00:03:21.750 smudge in the eyepiece. Slide westward to Sagitta, 00:03:21.990 --> 00:03:25.830 the tiny arrow pointing between Aquila and Volpecula. 00:03:26.310 --> 00:03:30.150 Here you'll find M71, a cluster that sits right 00:03:30.150 --> 00:03:33.550 on the border between open and globular, granular, 00:03:33.870 --> 00:03:37.090 loosely packed, and striking at medium power. 00:03:38.030 --> 00:03:42.889 Up in Volpecula, telescopes reveal NGC 6940, 00:03:43.370 --> 00:03:48.080 a lush field of faint suns. In Scutum, the wild 00:03:48.080 --> 00:03:52.340 duck cluster M11 is one of the sky's finest open 00:03:52.340 --> 00:03:56.060 clusters with stars packed like glitter. And 00:03:56.060 --> 00:04:01.599 for a challenge, hunt nearby for IC1295, a delicate 00:04:01.599 --> 00:04:04.680 planetary nebula that responds beautifully to 00:04:04.680 --> 00:04:09.340 an O3 filter. Faint little Equelius, the little 00:04:09.340 --> 00:04:12.979 horse near Delphinus, offers a fine double star, 00:04:13.500 --> 00:04:18.240 Epsilon Equilii, a classic seeing test. And in 00:04:18.240 --> 00:04:21.079 Lacerda, the lizard crawling high overhead later 00:04:21.079 --> 00:04:27.160 at night, NGC 7243 sprawls as a pleasing scattered 00:04:27.160 --> 00:04:31.360 open cluster. The Milky Way still arcs bright 00:04:31.360 --> 00:04:34.399 through the south in early evening, but the moon's 00:04:34.399 --> 00:04:36.819 glow will wash it out more and more as the week 00:04:36.819 --> 00:04:40.060 goes on. Take advantage of the first few nights 00:04:40.060 --> 00:04:42.860 after midnight for darker glimpses, then shift 00:04:42.860 --> 00:04:46.120 your focus to planets, clusters, and lunar landscapes 00:04:46.120 --> 00:04:50.060 once the moon dominates. Next week brings the 00:04:50.060 --> 00:04:53.060 full moon and elsewhere in the world a total 00:04:53.060 --> 00:04:56.240 lunar eclipse, but it's not visible here in the 00:04:56.240 --> 00:05:00.040 Americas. You may have heard the Latin expression 00:05:00.040 --> 00:05:03.839 tempus fugit, which simply means time flies. 00:05:04.540 --> 00:05:07.040 We're going to examine that in a very literal 00:05:07.040 --> 00:05:11.459 way as we explore watches in space, atomic clocks, 00:05:11.720 --> 00:05:15.240 and how time passes on other planets. That's 00:05:15.240 --> 00:05:31.000 coming up after the break. Stay with us. Welcome 00:05:31.000 --> 00:05:34.560 back! Let's take a break from the sky and talk 00:05:34.560 --> 00:05:37.680 about something we can't escape, no matter what 00:05:37.680 --> 00:05:42.420 planet we're on. Time. Here on Earth, time feels 00:05:42.420 --> 00:05:46.699 fixed. The sun rises, the sun sets, and our clocks 00:05:46.699 --> 00:05:49.839 keep a steady rhythm. But once you leave Earth, 00:05:50.000 --> 00:05:53.160 or even just start thinking like an interplanetary 00:05:53.160 --> 00:05:56.860 explorer, time starts to slip and bend in ways 00:05:56.860 --> 00:06:00.300 that are both subtle and profound. Let's start 00:06:00.300 --> 00:06:03.939 with Mars. A Martian day, or what scientists 00:06:03.939 --> 00:06:08.920 call a Sol, lasts 24 hours, 39 minutes, and 35 00:06:08.920 --> 00:06:12.439 seconds. Only about 40 minutes longer than an 00:06:12.439 --> 00:06:15.720 Earth day, but enough to wreak havoc on human 00:06:15.720 --> 00:06:19.379 schedules. Whenever NASA sends a rover, like 00:06:19.379 --> 00:06:22.740 Spirit, Opportunity, Curiosity, or Perseverance, 00:06:23.160 --> 00:06:26.699 the mission team shifts to Mars time. Their schedules 00:06:26.699 --> 00:06:30.240 drift by 40 minutes each day, so within a couple 00:06:30.240 --> 00:06:32.939 of weeks, scientists are working the night shift, 00:06:33.120 --> 00:06:36.399 then the day shift, then back again. It's a jet 00:06:36.399 --> 00:06:40.339 lag without ever leaving Pasadena. Families of 00:06:40.339 --> 00:06:43.139 engineers even reported being pulled into this 00:06:43.139 --> 00:06:46.300 Martian rhythm, living in a haze of perpetual 00:06:46.300 --> 00:06:50.000 time zone changes. It's known as Martian insomnia. 00:06:50.399 --> 00:06:54.279 The engineers at JPL actually commissioned Mars 00:06:54.279 --> 00:06:57.360 watches. They look like ordinary chronographs, 00:06:57.399 --> 00:07:00.040 but the second hand ticks just a little slower, 00:07:00.620 --> 00:07:03.439 stretching the day to match a soul. It's one 00:07:03.439 --> 00:07:05.600 of the few times in history people have worn 00:07:05.600 --> 00:07:09.240 a watch calibrated to another planet. And that 00:07:09.240 --> 00:07:13.079 brings me to a portion of the show I call Watches 00:07:13.079 --> 00:07:18.069 in Space! First off, I'm a geek when it comes 00:07:18.069 --> 00:07:21.970 to watches in general. Watches worn by astronauts 00:07:21.970 --> 00:07:25.129 are a niche interest of mine, one that peaked 00:07:25.129 --> 00:07:28.149 a few years ago when I saw in person the Omega 00:07:28.149 --> 00:07:32.759 Speedmaster worn by astronaut Charles Duke. I 00:07:32.759 --> 00:07:35.459 once had the opportunity to meet shuttle astronaut 00:07:35.459 --> 00:07:38.819 Clayton Anderson, and I spent most of that time 00:07:38.819 --> 00:07:42.639 talking to him about ham radio on the ISS and, 00:07:42.680 --> 00:07:47.399 of course, his Omega X -33 watch. The tradition 00:07:47.399 --> 00:07:51.420 of timekeeping in space runs deep. Early in human 00:07:51.420 --> 00:07:55.600 space exploration, NASA selected the Omega Speedmaster 00:07:55.600 --> 00:07:59.579 Chronograph, a fully mechanical hand -wound watch. 00:08:00.779 --> 00:08:03.860 Mechanical watches can't crash or short out in 00:08:03.860 --> 00:08:07.620 a vacuum or when exposed to radiation. Additionally, 00:08:07.800 --> 00:08:10.579 the Speedmaster has an acrylic crystal, that's 00:08:10.579 --> 00:08:14.139 the glass over the dial, which is shatter -resistant, 00:08:14.279 --> 00:08:16.980 unlike the sapphire crystals that are often used 00:08:16.980 --> 00:08:20.819 in luxury timepieces. In old mission photos, 00:08:21.000 --> 00:08:23.519 you can see astronauts wearing the Speedmaster 00:08:23.519 --> 00:08:26.439 strapped over the wrist of their spacesuit during 00:08:26.439 --> 00:08:30.939 Gemini, EVAs, and on moonwalks. My favorite image 00:08:30.939 --> 00:08:34.159 of the Speedmaster was taken on Apollo 11, being 00:08:34.159 --> 00:08:37.480 worn by Buzz Aldrin inside the command module. 00:08:38.559 --> 00:08:41.659 Once on the lunar surface, Neil Armstrong actually 00:08:41.659 --> 00:08:44.580 left his watch in the lunar module as a backup 00:08:44.580 --> 00:08:48.139 timer, so it was Aldrin's that became the first 00:08:48.139 --> 00:08:52.139 watch on the moon. If you've seen the film Apollo 00:08:52.139 --> 00:08:55.220 13, you might remember when a crucial course 00:08:55.220 --> 00:08:58.580 correction burn was timed by the stopwatch hand 00:08:58.580 --> 00:09:02.480 on the Speedmaster, or Speedy, as it's affectionately 00:09:02.480 --> 00:09:07.139 known in watch nerd circles. Omega has embraced 00:09:07.139 --> 00:09:09.779 this history and still produces the original 00:09:09.779 --> 00:09:13.789 Moonwatch to this day. They include a NASA -style 00:09:13.789 --> 00:09:17.330 nylon strap you can attach for real astronaut 00:09:17.330 --> 00:09:20.450 authenticity, along with the engraving First 00:09:20.450 --> 00:09:23.889 Watch on the Moon on the case back. If you have 00:09:23.889 --> 00:09:26.350 7 grand or so burning a hole in your pocket, 00:09:26.450 --> 00:09:30.149 it can be yours. Or you can buy the plastic look 00:09:30.149 --> 00:09:35.389 -alike Moon Swatch for about $270. This one is 00:09:35.389 --> 00:09:38.190 a special edition from Omega's parent company, 00:09:38.450 --> 00:09:41.460 The Swatch Group. If you grew up in the 80s, 00:09:41.500 --> 00:09:44.379 you might remember the swatch watch, those colorful 00:09:44.379 --> 00:09:47.639 plastic timepieces that were all the rage, along 00:09:47.639 --> 00:09:51.419 with neon colors on everything, parachute pants, 00:09:51.820 --> 00:09:55.200 jelly bracelets, and trapper keepers. The Omega 00:09:55.200 --> 00:09:58.460 isn't the only moon watch. Bulova makes a version 00:09:58.460 --> 00:10:02.059 inspired by watches worn on the Apollo 15 mission, 00:10:02.500 --> 00:10:05.179 although it eschews the mechanical innards for 00:10:05.179 --> 00:10:08.019 a super -accurate, high -beat quartz movement. 00:10:08.269 --> 00:10:12.269 NASA isn't as picky about watches nowadays. Crews 00:10:12.269 --> 00:10:15.889 have worn zens, fortices, and even digital watches. 00:10:16.730 --> 00:10:19.029 Today, astronauts often bring their personal 00:10:19.029 --> 00:10:22.549 watches like Garmin's and Apple watches. But 00:10:22.549 --> 00:10:25.789 the core idea is the same. You need reliable 00:10:25.789 --> 00:10:28.789 timekeeping when every maneuver, every engine 00:10:28.789 --> 00:10:32.190 burn, and every oxygen check is a lie for death. 00:10:32.490 --> 00:10:35.090 And there's just something kind of cool about 00:10:35.090 --> 00:10:37.929 knowing that something as everyday and ordinary 00:10:37.929 --> 00:10:41.409 as a wristwatch can be used as a tool for space 00:10:41.409 --> 00:10:45.029 exploration. But what happens when you need extreme 00:10:45.029 --> 00:10:48.570 precision? Right now your phone's navigation 00:10:48.570 --> 00:10:52.889 app depends on clocks in space, the atomic clocks 00:10:52.889 --> 00:10:57.690 onboard GPS satellites. Each satellite carries 00:10:57.690 --> 00:11:01.309 multiple clocks tuned to within billionths of 00:11:01.309 --> 00:11:04.529 a second. The system works by measuring how long 00:11:04.529 --> 00:11:07.529 it takes signals to reach your device. Even the 00:11:07.529 --> 00:11:10.750 tiniest error in timing would put you miles off 00:11:10.750 --> 00:11:14.470 course. And here's where relativity sneaks in. 00:11:14.889 --> 00:11:17.629 Einstein showed us that time doesn't tick the 00:11:17.629 --> 00:11:21.190 same everywhere. If you move very fast, your 00:11:21.190 --> 00:11:24.009 clock slows down compared to someone standing 00:11:24.009 --> 00:11:28.399 still. That's special relativity. If you climb 00:11:28.399 --> 00:11:31.159 higher out of a planet's gravity, your clock 00:11:31.159 --> 00:11:34.919 actually ticks faster, and that's general relativity. 00:11:36.100 --> 00:11:40.100 GPS satellites are in both situations at once. 00:11:40.279 --> 00:11:43.059 They're zipping around Earth at nearly 9 ,000 00:11:43.059 --> 00:11:45.940 miles per hour, which makes their clocks run 00:11:45.940 --> 00:11:50.000 a little slow. But they're also about 12 ,500 00:11:50.000 --> 00:11:53.860 miles above Earth's surface in weaker gravity, 00:11:54.159 --> 00:11:57.269 which makes their clocks run a little fast. Add 00:11:57.269 --> 00:11:59.990 the two effects together, and the fast wins. 00:12:00.330 --> 00:12:03.529 Their clocks tick about 38 microseconds ahead 00:12:03.529 --> 00:12:06.929 each day compared to clocks on Earth. That sounds 00:12:06.929 --> 00:12:09.809 tiny, but if engineers didn't correct for it, 00:12:10.009 --> 00:12:13.210 your location on Google Maps would drift by several 00:12:13.210 --> 00:12:16.710 miles in a matter of hours. In other words, without 00:12:16.710 --> 00:12:19.909 taking relativity into account, we'd all be lost. 00:12:20.320 --> 00:12:23.320 So, whether it's engineers struggling to live 00:12:23.320 --> 00:12:27.059 on Martian time, astronauts strapping speed masters 00:12:27.059 --> 00:12:30.059 to their sleeves, or atomic clocks whispering 00:12:30.059 --> 00:12:33.340 to your smartphone, space reminds us that time 00:12:33.340 --> 00:12:37.200 is not universal. It's a local rhythm, tied to 00:12:37.200 --> 00:12:40.519 gravity, velocity, and the turning of worlds. 00:12:41.500 --> 00:12:45.120 Here on Earth, we march to a 24 -hour beat. On 00:12:45.120 --> 00:12:48.860 Mars, the tempo slows by 40 minutes. In orbit, 00:12:49.379 --> 00:12:52.039 atomic clocks tick just differently enough to 00:12:52.039 --> 00:12:56.279 keep us humble. Time is not some absolute metronome 00:12:56.279 --> 00:12:59.360 in the background of the universe. It's pliable 00:12:59.360 --> 00:13:03.460 and contextual. And as we push farther into space, 00:13:03.740 --> 00:13:06.080 we'll discover just how many ways we can bend 00:13:06.080 --> 00:13:14.370 it, stretch it, and live by it. If the stars 00:13:14.370 --> 00:13:16.850 spoke to you this week or if a question's been 00:13:16.850 --> 00:13:19.570 on your mind, I'd love to hear it. Visit our 00:13:19.570 --> 00:13:23.129 website, StarTrails .Show, where you can contact 00:13:23.129 --> 00:13:27.149 me and explore past episodes. Be sure to follow 00:13:27.149 --> 00:13:30.669 us on Blue Sky and YouTube. Links are in the 00:13:30.669 --> 00:13:33.669 show notes. Until we meet again beneath the stars, 00:13:34.269 --> 00:13:35.269 clear skies, everyone.