1 00:00:08,000 --> 00:00:11,000 Your guide to constellations, deep-sky objects, 2 00:00:11,020 --> 00:00:13,700 planets and events. Tonight's Sky, 3 00:00:13,700 --> 00:00:19,000 Tonight's Sky, highlights of the February sky. 4 00:00:37,880 --> 00:00:41,600 Mars and Venus accompany each other in the west 5 00:00:41,640 --> 00:00:45,000 after sunset. 6 00:00:54,320 --> 00:00:58,200 Use a telescope to search for features on Mars 7 00:00:58,200 --> 00:01:00,400 or the crescent phase of Venus. 8 00:01:15,500 --> 00:01:19,400 The winter night sky, filled with brilliant stars, 9 00:01:19,400 --> 00:01:24,000 presents one of the best celestial views. 10 00:01:30,500 --> 00:01:34,100 Orion, the great hunter of Greek mythology, 11 00:01:34,100 --> 00:01:39,660 dominates the winter sky. 12 00:01:39,660 --> 00:01:43,700 This constellation is among the easiest to recognize. 13 00:01:43,760 --> 00:01:47,700 It is full of young stars, dying stars, 14 00:01:47,700 --> 00:01:49,300 and many nebulae. 15 00:01:49,300 --> 00:01:52,700 Betelgeuse, one of Orion's "shoulders," 16 00:01:52,700 --> 00:01:55,300 is a red supergiant star 17 00:01:55,300 --> 00:01:58,740 about 650 times bigger than the Sun. 18 00:01:58,780 --> 00:02:04,700 It shines with the brightness of tens of thousands of Suns. 19 00:02:06,680 --> 00:02:10,300 Betelgeuse is near the end of its life. 20 00:02:10,360 --> 00:02:14,000 With the fuel at the Star's core practically depleted, 21 00:02:14,000 --> 00:02:17,320 the core has contracted and heated, 22 00:02:17,320 --> 00:02:21,520 causing the outer gaseous layers of the star to swell. 23 00:02:23,940 --> 00:02:28,720 Rigel, one of Orion's "knees," is a triple-star system 24 00:02:28,780 --> 00:02:34,200 made up of two smaller stars orbiting a blue supergiant. 25 00:02:34,280 --> 00:02:39,200 Rigel's blue supergiant star has a short lifespan. 26 00:02:39,220 --> 00:02:43,800 Blue supergiant stars are much hotter than our Sun 27 00:02:43,800 --> 00:02:47,040 and use up their fuel quickly. 28 00:02:47,700 --> 00:02:51,100 Orion's Belt is easy to spot. 29 00:02:51,140 --> 00:02:56,400 It is made up of three stars, Alnitak, Alnilam, 30 00:02:56,420 --> 00:03:00,100 and Mintaka. 31 00:03:00,180 --> 00:03:02,620 From the left side of Orion's Belt, 32 00:03:02,620 --> 00:03:06,100 look down to the Great Orion Nebula. 33 00:03:06,120 --> 00:03:08,900 Although barely visible to the naked eye, 34 00:03:08,940 --> 00:03:13,000 it is the brightest diffuse gas cloud in the night sky. 35 00:03:13,000 --> 00:03:16,300 ("Nebula" is Latin for "cloud.") 36 00:03:16,300 --> 00:03:19,500 A small telescope unveils the details 37 00:03:19,500 --> 00:03:23,400 and grandeur of the nebula. 38 00:03:28,200 --> 00:03:32,780 Embedded inside the Orion Nebula is the Trapezium, 39 00:03:32,860 --> 00:03:36,200 a group of hot young stars so brilliant 40 00:03:36,220 --> 00:03:40,500 they cause the surrounding gas to glow. 41 00:03:56,480 --> 00:03:59,560 Canis Major, the Great Dog, 42 00:03:59,580 --> 00:04:04,340 is the faithful companion who follows in Orion's footsteps. 43 00:04:05,700 --> 00:04:08,500 Canis Major is dominated by the most 44 00:04:08,500 --> 00:04:12,500 brilliant star in the night sky, Sirius. 45 00:04:12,580 --> 00:04:16,000 Sirius is actually a double system, 46 00:04:16,100 --> 00:04:18,400 containing a bright star 47 00:04:18,400 --> 00:04:22,400 and a much smaller and fainter companion. 48 00:04:22,400 --> 00:04:26,240 It is a mere 8.6 light-years away. 49 00:04:26,270 --> 00:04:29,600 Scanning with binoculars just below Sirius 50 00:04:29,620 --> 00:04:35,200 will reveal a lovely cluster of stars called M41. 51 00:04:35,220 --> 00:04:38,100 It contains about 100 stars 52 00:04:38,140 --> 00:04:41,220 including several red giants. 53 00:04:41,240 --> 00:04:45,700 Stars in clusters like M41 were born together 54 00:04:45,740 --> 00:04:50,000 and are all about the same age. 55 00:05:02,680 --> 00:05:06,720 Jupiter ascends into the eastern sky around midnight 56 00:05:06,740 --> 00:05:09,300 and climbs high into the southeast 57 00:05:09,380 --> 00:05:12,500 during the early morning hours. 58 00:05:17,600 --> 00:05:21,800 Aim a telescope at Jupiter to view its cloud bands 59 00:05:21,800 --> 00:05:26,540 and to see how many of its moons you can spot. 60 00:05:37,040 --> 00:05:40,200 Saturn follows Jupiter into the southeast 61 00:05:40,200 --> 00:05:43,040 a few hours later. 62 00:05:51,100 --> 00:05:53,000 Catch a glimpse of Saturn's rings through a telescope 63 00:05:54,420 --> 00:05:57,160 before the Sun comes up. 64 00:06:09,310 --> 00:06:12,190 Visible throughout most of the world, 65 00:06:12,190 --> 00:06:15,930 a penumbral lunar eclipse occurs in the late evening 66 00:06:15,980 --> 00:06:20,100 of February 10th or the early morning of February 11th, 67 00:06:20,100 --> 00:06:22,500 depending on the viewing location. 68 00:06:22,510 --> 00:06:25,030 The Moon will darken slightly 69 00:06:25,030 --> 00:06:30,300 as it passes through the outer edges of Earth's shadow. 70 00:06:30,340 --> 00:06:32,460 On February 26th, 71 00:06:32,460 --> 00:06:36,900 parts of South America, Africa, and Antarctica 72 00:06:36,900 --> 00:06:40,700 will be treated to either a partial solar eclipse 73 00:06:40,700 --> 00:06:42,900 or an annular eclipse, when the 74 00:06:42,960 --> 00:06:46,900 when the Moon blocks all but the outer edge of the Sun, 75 00:06:46,960 --> 00:06:51,400 leaving a glowing "ring of fire."