WEBVTT 00:00:07.449 --> 00:00:10.310 Howdy Star Gazers, and welcome to this episode 00:00:10.310 --> 00:00:13.890 of Star Trails. I'm Drew, and I'll be your guide 00:00:13.890 --> 00:00:16.210 to the night sky for the week starting March 00:00:16.210 --> 00:00:20.410 the 23rd through the 29th. This week we have 00:00:20.410 --> 00:00:23.989 a waning crescent moon, a lineup of bright planets, 00:00:24.410 --> 00:00:27.829 and an upcoming partial solar eclipse, though 00:00:27.829 --> 00:00:31.339 it won't be visible from many places. We'll tour 00:00:31.339 --> 00:00:35.119 through the spring constellations Virgo and Cancer, 00:00:35.719 --> 00:00:38.420 and we'll examine how the first image of a black 00:00:38.420 --> 00:00:42.479 hole was created using a planet -sized telescope. 00:00:43.079 --> 00:00:45.920 So, grab a comfortable spot under the night sky 00:00:45.920 --> 00:00:50.560 and let's get started. The moon starts this week 00:00:50.560 --> 00:00:53.820 in its waning crescent phase, meaning it's getting 00:00:53.820 --> 00:00:56.780 smaller each night as it approaches the new moon 00:00:56.780 --> 00:01:00.799 on March 29th. If you're up before dawn, look 00:01:00.799 --> 00:01:03.659 for a thin sliver of moonlight in the eastern 00:01:03.659 --> 00:01:07.799 sky, especially earlier in the week. With less 00:01:07.799 --> 00:01:10.739 moonlight washing out the sky, this is the perfect 00:01:10.739 --> 00:01:13.879 time to catch a glimpse of faint galaxies, nebula, 00:01:14.159 --> 00:01:18.780 and star clusters. On March 29th, the new moon 00:01:18.780 --> 00:01:21.060 means the moon will be completely invisible, 00:01:21.420 --> 00:01:25.609 offering an ideal night for stargazing. Venus, 00:01:25.870 --> 00:01:28.650 now the morning star, is beginning to rise in 00:01:28.650 --> 00:01:32.049 the pre -dawn eastern sky. If you're an early 00:01:32.049 --> 00:01:35.189 riser, watch for Venus low on the horizon just 00:01:35.189 --> 00:01:39.450 before sunrise. Mars will be visible after sunset, 00:01:39.750 --> 00:01:42.549 hanging in the sky for more than nine hours into 00:01:42.549 --> 00:01:45.989 the late evening. With its reddish hue, it's 00:01:45.989 --> 00:01:49.730 easy to spot in Gemini, near the twin stars Castor 00:01:49.730 --> 00:01:53.680 and Pollux. Jupiter is still one of the brightest 00:01:53.680 --> 00:01:57.019 objects in the night sky, best seen just after 00:01:57.019 --> 00:02:00.219 sunset. It's fairly high in the western sky, 00:02:00.560 --> 00:02:08.639 hanging out in Taurus. As we look towards April, 00:02:08.840 --> 00:02:12.060 let's take a moment to spotlight two constellations 00:02:12.060 --> 00:02:15.680 that signal the arrival of spring, Virgo and 00:02:15.680 --> 00:02:19.599 Cancer. Both have unique characteristics and 00:02:19.599 --> 00:02:22.439 house some stunning deep sky objects that are 00:02:22.439 --> 00:02:26.819 worth exploring. Virgo, the maiden of the skies, 00:02:27.039 --> 00:02:29.719 is one of the largest constellations and plays 00:02:29.719 --> 00:02:33.680 a major role in spring stargazing. It's also 00:02:33.680 --> 00:02:37.240 one of the 12 zodiac constellations and is often 00:02:37.240 --> 00:02:40.759 associated with harvest and fertility myths across 00:02:40.759 --> 00:02:44.979 different cultures. Virgo is best identified 00:02:44.979 --> 00:02:48.780 by its brightest star, Spica, a brilliant blue 00:02:48.780 --> 00:02:52.639 -white star that sits about 260 light years away 00:02:52.639 --> 00:02:57.080 from Earth. Spica is a binary star system, two 00:02:57.080 --> 00:03:00.199 stars locked in a close dance around each other. 00:03:01.759 --> 00:03:05.240 To locate Virgo, draw an imaginary arc from the 00:03:05.240 --> 00:03:08.740 handle of the Big Dipper to Arcturus in Boötes, 00:03:09.479 --> 00:03:13.210 and then extend it downward to Spica. This is 00:03:13.210 --> 00:03:16.969 the famous stargazing guide, arc to Arcturus, 00:03:17.250 --> 00:03:21.770 then speed on to Spica. Virgo is home to some 00:03:21.770 --> 00:03:24.590 of the richest galaxy fields in the night sky. 00:03:24.849 --> 00:03:28.210 Some of the most famous objects include the Virgo 00:03:28.210 --> 00:03:31.669 Cluster of Galaxies. This enormous collection 00:03:31.669 --> 00:03:35.129 of galaxies is about 50 million light years away 00:03:35.129 --> 00:03:39.479 and can be found between Leo and Virgo. The cluster 00:03:39.479 --> 00:03:43.180 contains more than 1 ,300 spiral, elliptical, 00:03:43.419 --> 00:03:46.599 and irregular galaxies, many of which can be 00:03:46.599 --> 00:03:50.639 seen with a medium -sized telescope. Messier 00:03:50.639 --> 00:03:54.219 87 is one of the brightest galaxies in the Virgo 00:03:54.219 --> 00:03:58.860 cluster. M87 is a giant elliptical galaxy and 00:03:58.860 --> 00:04:01.539 is famous for being the home of the first black 00:04:01.539 --> 00:04:06.379 hole ever imaged back in 2019. We'll talk about 00:04:06.379 --> 00:04:08.819 how that image was created in the second half 00:04:08.819 --> 00:04:11.780 of the show. If you have a telescope, you might 00:04:11.780 --> 00:04:14.699 just catch a glimpse of its faint glowing core. 00:04:15.780 --> 00:04:20.560 The Sombrero Galaxy M104 is an edge -on spiral 00:04:20.560 --> 00:04:24.000 galaxy that looks like a Sombrero hat, with a 00:04:24.000 --> 00:04:26.660 bright central bulge and a dust lane cutting 00:04:26.660 --> 00:04:30.740 across it. Located just outside the Virgo cluster, 00:04:31.040 --> 00:04:35.759 M104 is 28 million light -years away, and shines 00:04:35.759 --> 00:04:38.759 at a magnitude of 8, making it a great target 00:04:38.759 --> 00:04:43.699 for small telescopes. Now let's shift to a constellation 00:04:43.699 --> 00:04:47.079 that doesn't always get as much love, Cancer 00:04:47.079 --> 00:04:51.399 the Crab. Cancer is one of the faintest zodiac 00:04:51.399 --> 00:04:54.439 constellations, but it holds some amazing deep 00:04:54.439 --> 00:04:59.120 sky objects. Cancer sits between Gemini and Leo. 00:04:59.269 --> 00:05:02.170 Since it lacks bright stars, the best way to 00:05:02.170 --> 00:05:04.589 locate it is by looking between the bright twin 00:05:04.589 --> 00:05:08.829 stars of Castor and Pollux, and the star Regulus 00:05:08.829 --> 00:05:12.470 in Leo. Once you find this faint region, you're 00:05:12.470 --> 00:05:16.430 looking at Cancer. Cancer is home to one of the 00:05:16.430 --> 00:05:20.089 best open star clusters in the entire night sky, 00:05:20.589 --> 00:05:26.509 the Beehive cluster M44. This swarm of stars 00:05:26.509 --> 00:05:29.449 is one of the brightest and closest open star 00:05:29.449 --> 00:05:34.129 clusters to Earth, just 577 light -years away. 00:05:34.850 --> 00:05:37.829 It contains more than a thousand stars, many 00:05:37.829 --> 00:05:41.050 of which are similar to our Sun, making it one 00:05:41.050 --> 00:05:44.290 of the most rewarding sites for backyard astronomers. 00:05:46.050 --> 00:05:48.750 In dark skies, it's visible to the naked eye, 00:05:48.750 --> 00:05:52.500 appearing as a hazy patch. A pair of binoculars 00:05:52.500 --> 00:05:56.079 will reveal dozens of bright stars swarming together, 00:05:56.500 --> 00:06:00.379 just like bees in a hive. Telescope owners may 00:06:00.379 --> 00:06:05.040 want to chase down M67, one of the oldest open 00:06:05.040 --> 00:06:08.240 clusters. Perhaps even more intriguing than the 00:06:08.240 --> 00:06:12.720 beehive cluster, M67 is estimated to be 4 billion 00:06:12.720 --> 00:06:16.060 years old, meaning some of its stars are nearly 00:06:16.060 --> 00:06:20.519 as old as our Sun. It contains around 500 stars 00:06:20.519 --> 00:06:25.199 and lies about 2 ,700 light years away. Astronomers 00:06:25.199 --> 00:06:28.800 study it to understand how sun -like stars evolve 00:06:28.800 --> 00:06:34.139 over time. M67 is visible in binoculars, although 00:06:34.139 --> 00:06:37.160 a telescope will reveal more individual stars 00:06:37.160 --> 00:06:47.769 packed into its core. A partial sunrise solar 00:06:47.769 --> 00:06:52.069 eclipse is happening on March the 29th, but sadly 00:06:52.069 --> 00:06:55.230 it's not visible for most of us here in the States. 00:06:56.310 --> 00:06:58.750 A partial solar eclipse happens when the Moon 00:06:58.750 --> 00:07:01.310 passes between the Earth and the Sun, but they 00:07:01.310 --> 00:07:04.769 don't align perfectly. This results in the Moon 00:07:04.769 --> 00:07:07.930 covering only a portion of the Sun's disk, taking 00:07:07.930 --> 00:07:11.949 a characteristic bite out of the Sun. In the 00:07:11.949 --> 00:07:14.850 northeastern United States and eastern Canada, 00:07:15.170 --> 00:07:18.870 the eclipse will be visible at sunrise. For example, 00:07:19.009 --> 00:07:21.930 in Hartford, Connecticut, the event starts around 00:07:21.930 --> 00:07:26.449 6 .38 a .m. Eastern Daylight Time, reaches its 00:07:26.449 --> 00:07:32.389 maximum at 6 .41, and concludes by 7 .07 a .m. 00:07:33.069 --> 00:07:35.889 The best views in the U .S. will be in northeastern 00:07:35.889 --> 00:07:39.670 Maine, where up to 85 % of the sun will be obscured 00:07:39.670 --> 00:07:43.889 at sunrise. This eclipse will be observable across 00:07:43.889 --> 00:07:47.370 much of Europe during the late morning. In London, 00:07:48.170 --> 00:07:50.750 approximately 30 % of the Sun will be obscured 00:07:50.750 --> 00:07:53.689 with the event occurring between 10 a .m. and 00:07:53.689 --> 00:08:06.680 noon GMT, peaking around 11 a .m. On April 10, 00:08:06.959 --> 00:08:10.300 2019, history was made when scientists released 00:08:10.300 --> 00:08:13.699 the first -ever image of a black hole, located 00:08:13.699 --> 00:08:17.439 in the center of the galaxy M87 in the Virgo 00:08:17.439 --> 00:08:20.720 Cluster. This groundbreaking achievement was 00:08:20.720 --> 00:08:23.120 the result of an international collaboration 00:08:23.120 --> 00:08:26.600 known as the Event Horizon Telescope Project, 00:08:27.360 --> 00:08:30.259 a network of radio telescopes around the world 00:08:30.259 --> 00:08:33.399 working together to capture an object that by 00:08:33.399 --> 00:08:37.700 its very nature, is invisible. A black hole is 00:08:37.700 --> 00:08:40.460 a region of space where gravity is so intense 00:08:40.460 --> 00:08:43.639 that nothing, not even light, can escape it. 00:08:44.120 --> 00:08:47.440 Black holes form when massive stars reach the 00:08:47.440 --> 00:08:50.080 end of their life cycles and collapse under their 00:08:50.080 --> 00:08:53.960 own gravity. This collapse can result in a stellar 00:08:53.960 --> 00:08:57.659 mass black hole, typically a few times the mass 00:08:57.659 --> 00:09:01.820 of our sun. or over billions of years grow into 00:09:01.820 --> 00:09:04.960 a supermassive black hole, such as that at the 00:09:04.960 --> 00:09:08.820 center of a galaxy. Supermassive black holes, 00:09:09.059 --> 00:09:12.679 like the one in M87, are millions or even billions 00:09:12.679 --> 00:09:16.679 of times the mass of our sun. Scientists believe 00:09:16.679 --> 00:09:19.759 they form over time, possibly from the merging 00:09:19.759 --> 00:09:23.019 of smaller black holes and the accumulation of 00:09:23.019 --> 00:09:27.139 vast amounts of matter. These cosmic giants exert 00:09:27.139 --> 00:09:30.320 tremendous gravitational influence, shaping the 00:09:30.320 --> 00:09:33.620 orbits of stars and affecting entire galaxies. 00:09:34.639 --> 00:09:36.879 One of the defining features of a black hole 00:09:36.879 --> 00:09:40.639 is the event horizon, the boundary beyond which 00:09:40.639 --> 00:09:44.639 nothing can return. Any matter or light that 00:09:44.639 --> 00:09:47.659 crosses this threshold is permanently lost to 00:09:47.659 --> 00:09:50.820 the singularity, a point where gravity is thought 00:09:50.820 --> 00:09:54.389 to become infinitely strong. Surrounding the 00:09:54.389 --> 00:09:58.350 event horizon is an accretion disk, a swirling 00:09:58.350 --> 00:10:01.490 superheated ring of gas and dust falling toward 00:10:01.490 --> 00:10:05.149 the black hole. This glowing material is what 00:10:05.149 --> 00:10:07.889 allows astronomers to detect and study black 00:10:07.889 --> 00:10:10.330 holes, even though the black holes themselves 00:10:10.330 --> 00:10:14.009 are invisible. The black hole that was imaged 00:10:14.009 --> 00:10:18.139 lies at the heart of M87. a giant elliptical 00:10:18.139 --> 00:10:21.659 galaxy in the Virgo cluster about 55 million 00:10:21.659 --> 00:10:24.899 light -years away from Earth. This black hole 00:10:24.899 --> 00:10:29.600 is a monster with a mass of 6 .5 billion times 00:10:29.600 --> 00:10:33.220 that of our Sun. It was chosen as the target 00:10:33.220 --> 00:10:35.860 of the Event Horizon telescope project because 00:10:35.860 --> 00:10:39.379 it's relatively close, cosmically speaking, making 00:10:39.379 --> 00:10:42.379 it one of the easiest supermassive black holes 00:10:42.379 --> 00:10:46.940 to observe. Also, it has an enormous event horizon, 00:10:47.159 --> 00:10:49.840 meaning it would cast a large shadow that could 00:10:49.840 --> 00:10:53.480 be detected. It's surrounded by a bright accretion 00:10:53.480 --> 00:10:56.320 disk, providing the perfect contrast to capture 00:10:56.320 --> 00:11:00.279 the black hole's silhouette. The Event Horizon 00:11:00.279 --> 00:11:03.559 Telescope isn't a single telescope, but a network 00:11:03.559 --> 00:11:06.500 of eight radio telescopes positioned around the 00:11:06.500 --> 00:11:10.620 world, from Chile to Hawaii, the U .S., Spain, 00:11:11.019 --> 00:11:14.860 and Antarctica. By linking these telescopes together, 00:11:15.320 --> 00:11:18.139 astronomers effectively created a planet -sized 00:11:18.139 --> 00:11:21.460 telescope using a technique called very -long 00:11:21.460 --> 00:11:26.039 baseline interferometry. The final image, assembled 00:11:26.039 --> 00:11:29.360 from petabytes of data, revealed the now famous 00:11:29.360 --> 00:11:33.600 fiery ring, a circular glow of superheated gas 00:11:33.600 --> 00:11:36.879 surrounding a dark central shadow, which is the 00:11:36.879 --> 00:11:41.149 event horizon of the black hole. The image provided 00:11:41.149 --> 00:11:44.409 direct evidence that black holes exist and behave 00:11:44.409 --> 00:11:48.789 as predicted by Einstein's relativity. It confirmed 00:11:48.789 --> 00:11:52.169 that black holes can be imaged and it gave scientists 00:11:52.169 --> 00:11:56.409 insight into how matter behaves in extreme gravitational 00:11:56.409 --> 00:12:00.070 environments. This image was only the beginning. 00:12:00.509 --> 00:12:03.769 The EHT has since produced a similar image of 00:12:03.769 --> 00:12:07.470 Sagittarius A, the black hole at the center of 00:12:07.470 --> 00:12:11.230 our Milky Way. and continues refining its methods 00:12:11.230 --> 00:12:14.190 to uncover even more secrets of the universe. 00:12:15.009 --> 00:12:17.149 While you can't see this black hole from your 00:12:17.149 --> 00:12:21.649 backyard, you can definitely see M87. And knowing 00:12:21.649 --> 00:12:24.169 that a supermassive black hole is right in the 00:12:24.169 --> 00:12:32.700 middle of it is a powerful idea to ponder. If 00:12:32.700 --> 00:12:35.080 you found this episode helpful, let me know, 00:12:35.240 --> 00:12:38.580 and feel free to send in your questions and observations. 00:12:39.240 --> 00:12:41.720 The easiest way to do that is by visiting our 00:12:41.720 --> 00:12:46.179 website, StarTrails .Show. This is also a great 00:12:46.179 --> 00:12:49.460 way to share the show with friends. Until next 00:12:49.460 --> 00:12:52.000 time, keep looking up and exploring the night 00:12:52.000 --> 00:12:54.039 sky. Clear skies everyone!