1 00:00:17,599 --> 00:00:19,136 This is the Hubblecast. 2 00:00:19,236 --> 00:00:22,837 News and images from the NASA / ESA Hubble Space Telescope. 3 00:00:22,880 --> 00:00:26,547 Travelling through time and space with our host, Dr. J 4 00:00:26,594 --> 00:00:31,317 EPISODE 17: New views of the skies. a.k.a. Dr. Joe Liske. 5 00:00:31,332 --> 00:00:34,128 Welcome to this special episode of the Hubblecast 6 00:00:34,185 --> 00:00:37,486 celebrating the International Year of Astronomy in 2009 7 00:00:37,588 --> 00:00:41,330 400 years ago, Galileo Galilei looked at the night sky 8 00:00:41,380 --> 00:00:43,752 through a telescope for the first time. 9 00:00:43,827 --> 00:00:46,968 So we have decided to produce a special series of podcasts 10 00:00:47,021 --> 00:00:49,832 about the telescope, this magnificent instrument 11 00:00:49,875 --> 00:00:53,517 that has changed our perception of the world around us. 12 00:00:54,188 --> 00:00:58,648 By taking our sense of sight far beyond the realm of our forebears' imagination 13 00:00:58,720 --> 00:01:01,786 these wonderful instruments, the telescopes, open the way 14 00:01:01,839 --> 00:01:04,560 to a deeper and more perfect understanding of nature. 15 00:01:04,607 --> 00:01:06,006 - René Descartes, 1637 16 00:01:06,041 --> 00:01:10,834 For millennia mankind gazed out into the mesmerising night sky 17 00:01:10,873 --> 00:01:16,755 without recognising the stars of our own Milky Way galaxy as other suns... 18 00:01:16,799 --> 00:01:21,396 or the billions of sister galaxies making up the rest of our Universe... 19 00:01:23,975 --> 00:01:30,855 or that we are merely punctuation in the Universe's 13.7 billion year long story. 20 00:01:30,923 --> 00:01:33,669 With only our eyes as observing tools 21 00:01:33,711 --> 00:01:37,201 we had no means of finding solar systems around other stars, 22 00:01:37,623 --> 00:01:42,125 or of determining whether life exists elsewhere in the Universe. 23 00:01:46,363 --> 00:01:50,458 Today we are well on our way to unraveling many of the mysteries of the Universe, 24 00:01:50,523 --> 00:01:53,986 living in what may be the most remarkable age of astronomical discovery. 25 00:01:54,427 --> 00:01:57,516 I'm Dr. J and I will be your guide to the telescope, 26 00:01:57,517 --> 00:02:02,193 that amazing instrument that proved to be mankind's gateway to the Universe. 27 00:02:05,447 --> 00:02:15,795 Eyes on the Skies the Story of the telescope. 28 00:02:17,292 --> 00:02:22,750 Four centuries ago, in 1609, a man walked out into the fields near his home. 29 00:02:22,811 --> 00:02:27,432 He pointed his home made telescope at the Moon, the planets and the stars. 30 00:02:27,501 --> 00:02:31,052 His name was Galileo Galilei. 31 00:02:32,528 --> 00:02:35,813 Astronomy would never be the same again. 32 00:02:56,117 --> 00:03:00,633 Today, 400 years after Galileo first pointed a telescope to the skies, 33 00:03:00,681 --> 00:03:05,702 astronomers use giant mirrors on remote mountain tops to survey the heavens. 34 00:03:07,053 --> 00:03:11,440 The telescopes collect faint chirps and whispers from outer space. 35 00:03:12,494 --> 00:03:15,987 Scientists have even launched telescopes into Earth orbit, 36 00:03:16,039 --> 00:03:19,160 high above the disturbing effects of our atmosphere. 37 00:03:21,694 --> 00:03:24,967 And the view has been breathtaking! 38 00:03:31,512 --> 00:03:34,884 However, Galileo did not in fact invent the telescope. 39 00:03:34,941 --> 00:03:37,211 That credit goes to Hans Lipperhey, 40 00:03:37,285 --> 00:03:40,779 a slightly obscure Dutch-German spectacle maker. 41 00:03:42,020 --> 00:03:45,946 But Hans Lipperhey never used this telescope to look at the stars. 42 00:03:45,986 --> 00:03:48,058 Instead, he thought his new invention 43 00:03:48,059 --> 00:03:51,256 would mainly benefit seafarers and soldiers. 44 00:03:52,083 --> 00:03:57,421 Lipperhey came from Middelburg, then a large trading city in the fledgling Dutch Republic. 45 00:04:02,442 --> 00:04:06,718 In 1608 Lipperhey found that when viewing a distant object 46 00:04:06,786 --> 00:04:11,514 through a convex and a concave lens the object would be magnified 47 00:04:11,515 --> 00:04:16,174 if the two lenses were placed at just the right distance from one another. 48 00:04:18,027 --> 00:04:20,897 The telescope was born! 49 00:04:22,126 --> 00:04:25,879 In September 1608 Lipperhey revealed his new invention 50 00:04:25,880 --> 00:04:28,336 to Prince Maurits of the Netherlands. 51 00:04:28,337 --> 00:04:31,277 He could not have chosen a more advantageous moment 52 00:04:31,278 --> 00:04:36,633 because at that time the Netherlands were embroiled in the 80 Year' War with Spain. 53 00:04:43,887 --> 00:04:47,759 The new spyglass could magnify objects and so it could reveal 54 00:04:47,760 --> 00:04:52,442 enemy ships and troops that were too distant to be seen by the unaided eye. 55 00:04:52,839 --> 00:04:55,295 A very useful invention indeed! 56 00:04:56,115 --> 00:05:00,234 But the Dutch government never granted Lipperhey a patent for his telescope. 57 00:05:00,660 --> 00:05:03,884 The reason was that other merchants also claimed the invention, 58 00:05:03,960 --> 00:05:07,556 especially Lipperhey's competitor Sacharias Janssen. 59 00:05:07,827 --> 00:05:10,150 The dispute was never resolved. 60 00:05:10,203 --> 00:05:11,509 And to this day, 61 00:05:11,510 --> 00:05:16,489 the true origins of the telescope remain shrouded in mystery. 62 00:05:17,609 --> 00:05:21,248 Italian astronomer Galileo Galilei, the father of modern physics, 63 00:05:21,249 --> 00:05:25,068 heard about the telescope and decided to build his own. 64 00:05:26,541 --> 00:05:30,031 "About ten months ago a report reached my ears 65 00:05:30,032 --> 00:05:35,007 that a certain Fleming had constructed a spyglass by means of which 66 00:05:35,008 --> 00:05:40,231 visible objects, though very distant from the eye of the observer, 67 00:05:40,291 --> 00:05:43,760 were distinctly seen as if nearby" 68 00:05:44,965 --> 00:05:47,757 Galileo was the greatest scientist of his time. 69 00:05:47,808 --> 00:05:50,799 He was also a strong supporter of the new worldview 70 00:05:50,855 --> 00:05:53,989 advocated by the Polish astronomer Nicolaus Copernicus, 71 00:05:53,990 --> 00:05:57,947 who proposed that the Earth orbited the Sun instead of the other way round. 72 00:05:59,717 --> 00:06:02,116 Based on what he had heard of the Dutch telescope, 73 00:06:02,184 --> 00:06:04,792 Galileo constructed his own instruments. 74 00:06:05,056 --> 00:06:07,194 They were of much better quality. 75 00:06:08,905 --> 00:06:12,924 "Finally, sparing neither labour nor expenses, 76 00:06:12,994 --> 00:06:17,733 I succeeded in constructing for myself so excellent an instrument 77 00:06:18,197 --> 00:06:23,790 that objects seen by means of it appeared nearly one thousand times larger 78 00:06:23,860 --> 00:06:27,504 than when regarded with our natural vision" 79 00:06:27,965 --> 00:06:31,664 It was time to train the telescope on the heavens. 80 00:06:34,322 --> 00:06:36,819 "I have been led to the opinion and conviction 81 00:06:36,820 --> 00:06:42,294 that the surface of the moon is not smooth, uniform and precisely spherical 82 00:06:42,358 --> 00:06:45,516 as a great number of philosophers believe to be, 83 00:06:45,517 --> 00:06:50,222 but is uneven, rough and full of cavities and prominences, 84 00:06:50,223 --> 00:06:53,831 being not unlike the face of the Earth" 85 00:07:00,071 --> 00:07:03,527 A landscape of craters, mountains and valleys. 86 00:07:04,179 --> 00:07:07,090 A world like our own! 87 00:07:07,701 --> 00:07:12,941 A few weeks later, in January 1610, Galileo looked at Jupiter. 88 00:07:13,484 --> 00:07:16,498 Close to the planet he saw four pricks of light 89 00:07:16,499 --> 00:07:21,136 that changed their position on the sky night after night along with Jupiter. 90 00:07:21,377 --> 00:07:25,817 It was like a slow, cosmic ballet of satellites orbiting the planet. 91 00:07:26,361 --> 00:07:31,498 These four pricks of light would come to be known as the Galilean moons of Jupiter. 92 00:07:32,462 --> 00:07:34,587 What else did Galileo discover? 93 00:07:35,157 --> 00:07:36,987 The faces of Venus! 94 00:07:37,040 --> 00:07:42,129 Just like the moon, Venus waxes and wanes from crescent to full and back again. 95 00:07:42,664 --> 00:07:46,298 Strange appendages on either side of Saturn. 96 00:07:46,926 --> 00:07:49,324 Dark spots on the face of the Sun. 97 00:07:49,796 --> 00:07:51,843 And, of course, stars. 98 00:07:51,903 --> 00:07:54,626 Thousands of them, maybe even millions. 99 00:07:54,627 --> 00:07:57,629 Each too faint to be seen by the naked eye. 100 00:07:57,927 --> 00:08:02,162 It was as if mankind had suddenly thrown off its blindfold. 101 00:08:02,163 --> 00:08:05,459 There was a whole Universe to discover out there. 102 00:08:11,668 --> 00:08:15,541 News about the telescope spread across Europe like wildfire. 103 00:08:16,353 --> 00:08:19,704 In Prague, at the court of Emperor Rudolph II, 104 00:08:19,705 --> 00:08:23,205 Johannes Kepler improved the design of the instrument. 105 00:08:23,768 --> 00:08:26,776 In Antwerp, Dutch cartographer Michael van Langren 106 00:08:26,780 --> 00:08:28,987 produced the first reliable maps of the moon, 107 00:08:29,002 --> 00:08:32,401 showing what he believed to be continents and oceans. 108 00:08:33,493 --> 00:08:37,213 And Johannes Hevelius, a wealthy brewer in Poland, 109 00:08:37,214 --> 00:08:40,883 built huge telescopes at his observatory in Danzig. 110 00:08:41,573 --> 00:08:46,125 This observatory was so large that it covered three rooftops! 111 00:08:47,551 --> 00:08:49,605 But the best instruments of the time 112 00:08:49,606 --> 00:08:53,429 were probably constructed by Christiaan Huygens in the Netherlands. 113 00:08:53,430 --> 00:08:58,816 In 1655, Huygens discovered Titan, the largest moon of Saturn. 114 00:08:59,336 --> 00:09:03,473 A few years later, his observations revealed Saturn's ring system, 115 00:09:03,530 --> 00:09:06,648 something Galileo had never understood. 116 00:09:08,604 --> 00:09:10,517 And last but not least: 117 00:09:10,518 --> 00:09:15,176 Huygens saw dark markings and bright polar caps on Mars. 118 00:09:15,770 --> 00:09:19,279 Could there be life on this remote, alien world? 119 00:09:19,662 --> 00:09:23,358 The question occupies astronomers to this day. 120 00:09:24,451 --> 00:09:27,557 The earliest telescopes were all refracting telescopes 121 00:09:27,558 --> 00:09:30,830 that used lenses to collect and bring together the starlight. 122 00:09:31,222 --> 00:09:33,817 Later, the lenses were replaced with mirrors. 123 00:09:34,093 --> 00:09:37,663 This reflecting telescope was first built by Niccolò Zucchi 124 00:09:37,664 --> 00:09:39,978 and later refined by Isaac Newton. 125 00:09:40,563 --> 00:09:43,990 Now in the late eighteenth century, the largest mirrors in the world 126 00:09:44,040 --> 00:09:48,049 were cast by William Herschel, an organist turned astronomer, 127 00:09:48,113 --> 00:09:50,340 who worked with his sister Caroline. 128 00:09:50,714 --> 00:09:52,768 In their house in Barth, in England, 129 00:09:52,822 --> 00:09:56,916 the Herschels poured red-hot molten metal into a mould 130 00:09:56,987 --> 00:09:59,012 and when the whole thing had cooled off 131 00:09:59,042 --> 00:10:02,985 they would polish the surface so that it would reflect starlight. 132 00:10:03,836 --> 00:10:08,314 During the course of his life, Herschel built more than 400 telescopes. 133 00:10:12,783 --> 00:10:15,190 The largest of these was so huge 134 00:10:15,244 --> 00:10:19,672 that it needed four servants to operate all the various ropes, wheels and pulleys 135 00:10:19,717 --> 00:10:24,264 that were required to track the motions of the stars across the night sky, 136 00:10:24,265 --> 00:10:27,577 which is of course caused by the Earth's rotation. 137 00:10:27,612 --> 00:10:29,683 Now Herschel was like a surveyor, 138 00:10:29,771 --> 00:10:34,941 he scanned the heavens and catalogued hundreds of new nebulae and binary stars. 139 00:10:34,942 --> 00:10:38,624 He also discovered that the Milky Way must be a flat disc 140 00:10:38,625 --> 00:10:42,726 and he even measured the motion of the Solar System through that disc 141 00:10:42,786 --> 00:10:46,593 by observing the relative motions of the stars and the planets. 142 00:10:47,293 --> 00:10:54,722 And then on the 13th of March in 1781, he discovered a new planet: Uranus. 143 00:10:54,775 --> 00:10:59,193 It was over 200 years until NASA's Voyager 2 spacecraft 144 00:10:59,194 --> 00:11:03,685 gave astronomers their first closer look of this distant world. 145 00:11:04,996 --> 00:11:08,604 In the lush and fertile countryside of central Ireland, 146 00:11:08,631 --> 00:11:13,685 William Parsons, the third Earl of Rosse, built the largest telescope of the nineteenth century. 147 00:11:14,902 --> 00:11:18,493 With a metal mirror a whopping 1.8 metres across, 148 00:11:18,494 --> 00:11:23,093 the giant telescope became known as "The Leviathan of Parsonstown". 149 00:11:23,590 --> 00:11:27,823 On the occasional clear, moonless nights, the Earl sat at the eyepiece, 150 00:11:27,891 --> 00:11:31,379 and sailed on a journey through the Universe. 151 00:11:33,499 --> 00:11:38,457 To the Orion Nebula, now known to be a stellar nursery. 152 00:11:38,674 --> 00:11:43,957 On to the mysterious Crab Nebula, the remnant of a supernova explosion. 153 00:11:44,042 --> 00:11:50,765 And the Whirlpool Nebula? Lord Rosse was its first to note the majestic spiral shape. 154 00:11:50,766 --> 00:11:56,696 A galaxy like our own, with intricate clouds of dark dust and glowing gas 155 00:11:56,697 --> 00:12:04,301 billions of individual stars and, who knows, maybe even planets like Earth. 156 00:12:06,941 --> 00:12:12,348 The telescope had become our vessel to explore the Universe. 157 00:12:16,890 --> 00:12:20,389 Thank you for joining me in this first episode of the special series. 158 00:12:20,390 --> 00:12:23,585 Today we have talked about the creation of the first telescopes 159 00:12:23,693 --> 00:12:27,539 and how they facilitated man's first steps out into the Universe. 160 00:12:27,859 --> 00:12:31,368 Next time we will see how astronomers use bigger and bigger mirrors 161 00:12:31,369 --> 00:12:33,706 to see further than ever before. 162 00:12:33,995 --> 00:12:36,627 This is Dr. J. signing off for the Hubblecast. 163 00:12:36,649 --> 00:12:40,646 Once again nature surprised us beyond our wildest imagination. 164 00:12:41,577 --> 00:12:43,577 Hubblecast is produced by ESA / Hubble 165 00:12:43,578 --> 00:12:45,578 at the European Southern Observatory in Germany. 166 00:12:46,684 --> 00:12:48,684 The Hubble mission is a project of international cooperation 167 00:12:48,685 --> 00:12:50,685 between NASA and the European Space Agency.