Solar System RMSC Strasenburgh Planetarium school show for grades 3-6

Transcription

1 Solar System 2006 RMSC Strasenburgh Planetarium school show for grades 3-6 Script for recorded narrations Script by Steve Fentress Copyright 2006 Rochester Museum & Science Center Rev. 3/8/06 "Solar System Exploration" timeline "Space Age" timeline Solar system exploration: a timeline of more than five centuries. First, let s look at the 1500 s. The yellow stripes show the lifetimes of Copernicus, Tycho, Galileo, Kepler and Newton. Those astronomers figured out that our Earth is a planet just like Mercury, Venus, Mars, Jupiter and Saturn, the other planets that had been known for centuries and that all the planets are held in their orbits by the gravity of our star, the sun. 1610: invention of the telescope. Using telescopes, an astronomer named Galileo found moons going around Jupiter. Other astronomers, Cassini and Huygens, discovered the rings and moons of Saturn. What planet was discovered in 1781? 1781 was near the end of the 1700 s look there for a planet it was Uranus. 1801: Ceres: the first asteroid discovered. 1851: what planet was discovered? 1851 is in the middle of the 1800 s it was Neptune. How about 1930? Pluto! Then, in the last part of the 1900 s we entered the age we are living in now: the Space Age. The Space Age: a timeline of six decades. During the Space Age we learned to build robot probes that could visit the planets. 1965: Mariner 4, the first spacecraft to take close-up pictures of Mars. A robot probe, no astronauts aboard, smaller than our star projector, launched by a rocket into space. Seven and a half 1

2 months later it zoomed past the planet Mars and, with its early type of TV camera, took 22 surprising pictures. Mars turned out to have craters like those on our moon. 1971: the Mariner 9 probe found dry riverbeds on Mars. The mystery: there's no liquid water on Mars. 1976: two Viking landers showed what you would see if you were standing on Mars. They also looked for signs of life and did not find any through 1989: Voyagers 1 and 2 visited Jupiter, Saturn, Uranus and Neptune Since 1990, the Hubble Space Telescope has been operating. 1997: Mars Pathfinder got to Mars with its Sojourner rover; so did Mars Global Surveyor, which is still posting pictures on the Internet. In 2004, two more American rovers landed on Mars. Our timeline shows mostly successful American missions. But not every mission succeeds. Many space probes either went off course or stopped working: Mars Climate Orbiter, Mars Polar Lander, Mars Observer, Mariner 8, Mariner 3, Mariner 1 and many Soviet probes. Interplanetary travel is very difficult. But for now: How do we learn about the planets and other features in our solar system? ESO telescope HST Goldstone Telescopes here on Earth help us look out into space. This telescope is in South America. How big is it? Look for the technician standing underneath. The Hubble Space Telescope does not go visit other planets, but it s up above Earth s atmosphere, where it has a very clear view. On your right: a radio telescope in California. Its main job: to communicate with space probes. It can also bounce radio waves off other planets and asteroids to find out what they are like. Cassini in shop 2

3 Finally, in the center, a space probe. This one is Cassini. It arrived at Saturn in It dropped a probe onto Saturn s moon Titan in CAD rendering of Cassini U.S. Capitol How do we make a space probe like Cassini and use it to find out about our solar system? First, many people work together to decide where a new space probe should go and what features it should have. They have to be careful: if the space probe has too many different parts it might be too big and heavy to launch into space, or it might cost too much. If it s an American mission, the United States Congress must vote to provide money to build the space probe. If Congress gives the OK Techs at work (Cassini/Huygens in shop, spacecraft components on a big white stand) Cassini nose fairing Cassini launch Artwork of Cassini trajectory Cassini near Saturn New music Stand of Trees Technicians work together to build the space probe. Then, they put the probe on top of a rocket and cover it with a protective shell called a nose fairing. The rocket takes off. Out in space, the nose fairing opens up and the space probe comes out. The probe travels through space. When the probe reaches its planet, moon, asteroid, or comet, it may fire a rocket engine to slow down before it turns on its camera to take pictures and send them back to Earth. Now, how do we get these pictures from space probes? To understand it, we might start by thinking about how we see something with our eyes, say trees outside on a sunny day. 3

4 Rays toward eye looking at trees Sunlight strikes the trees. "focus rays" and image appear on retina The trees reflect some sunlight toward our eye. The lens of our eye bends the light to make an image on the retina in our eyeball. The retina turns the image into messages that go to our brain. Silhouette head with eye, brain, and thought bubble Tree appears in thought bubble Stand of trees Add camera pointed at tree Our brain receives the messages, then we understand we're seeing trees. Now, compare to a digital camera. Sunlight strikes the trees. Add "focus rays" and detector surface Trees appear on detector chip Add cable and computer Tree on computer screen The camera lens bends the light to make an image on an image sensor that turns the image into messages a computer can use. Connect the camera to a computer with a cable. Messages travel from the camera, through the cable, to the computer. The computer uses the messages to make an image on a screen. We look at the screen and understand the image. How do we get a picture of a planet from a space probe? Saturn Spacecraft Sunlight strikes a planet. The planet reflects light toward the camera on the space probe. +callouts for camera, computer and radio on spacecraft 4

5 The camera sends messages through the space probe's computer to the RADIO TRANSMITTER. A radio transmitter turns messages into radio energy. It you have used a cell phone you have used one kind of radio transmitter. Schematic radio waves emitted from antenna (flashing) On the space probe, the radio energy comes out of the giant radio antenna and travels millions of miles across space to Earth Spacecraft antenna and Earth antenna looking at each other across great distance where another giant antenna receives the radio energy and turns it back into messages a computer can use. "Mission control" with planet image(s) on computer monitor(s), several people looking on Saturn appears on monitors SP south entrance Screen shot of JPL home page Finally, at mission control, images appear on computer screens. Scientists use their eyes and brains to look at the image on the screen and try to understand what they are seeing. Sometimes they will discuss an image for years before they agree on what a planet, moon, asteroid or comet is really like. How can YOU find out about the planets? You're invited to look through the telescope at the top of our observing tower on clear Saturday nights in the spring, summer and fall. You can also get a lot of good information from the Internet. But be careful to get your information only from reliable, trustworthy web pages. Mimas crater module You can study planet and moon pictures like a scientist. For example: Here s a picture of a small moon of Saturn called Mimas. It was taken by the Voyager 1 space probe. Mimas, labeled You can see a giant, cup-shaped pit: a crater. We have named this one Herschel Crater. 5

6 Herschel labeled Mimas, 240 mile diameter labeled Back to Herschel labeled Three Herschel-size ovals on Mimas Ditto with 240/3=80 Herschel with 80 mile callout Now, suppose you are told only one thing: the diameter of Mimas is 240 miles. Using just that information, how big is Herschel crater? Here s just one way you might figure it out. Ask yourself, how many times could Herschel Crater fit across all of Mimas? About three times. We know that all of Mimas is 240 miles across. 240 miles can hold about three Herschel craters. So the width of Herschel Crater is about 240 divided by 3, about 80 miles. End of Mimas crater module Rocket cam video You ve probably been told many times that you live on a planet, the Earth. But do you really believe it? Not sure? Perhaps this video will change your mind. This was the launch of the Stardust probe, which flew by a comet in Let's press fast forward. When we started out, we could see roads and grass on the ground. Now we are up far enough to see the curved shape of the earth. We can see the atmosphere, the blanket of air that covers our planet. There's the coast of Florida. Let's go back to normal "play" speed. The first stage of the rocket has used up all its fuel, so it drops away. Then a new rocket engine starts on the second stage. Video fades to black Rotating Earth effect 6

7 Rotating Earth off Our Earth, rotating every 24 hours to make day and night. Surface of Earth: 70 percent covered by water. We do not know of any other planet with liquid water oceans on its surface. A thin layer of air, our atmosphere, makes life as we know it possible. White clouds of water droplets drift through our atmosphere. Things stay on the Earth because of Earth s gravity. Every planet and moon has gravity, some more than others. But NOT every planet or moon has an atmosphere. Now let s travel much farther out. Solar system projector Our Sun title sun photo If we could somehow travel a couple of hundred million miles above the north pole of the Earth, and put time into fast forward, we might see something like this. At the center of our solar system: the star we call the Sun. We can see planets revolving around the sun. Closest to the sun: Mercury, then Venus, then our planet Earth, revolving around the sun once a year, then Mars, then the biggest planet in our solar system Jupiter. Between the orbits of Mars and Jupiter: the main asteroid belt, over one hundred thousand small rocky fragments that never became part of any planet. Beyond Jupiter, the planet famous for its rings, Saturn. Beyond Saturn, the planets are too far out to show in this picture. Uranus revolves more than twice as far out as Saturn. Neptune is so far out that it would be inside the dome for only a small part of each orbit. And Pluto, revolving around the sun every 248 years, would be out in the lobby waiting to buy a ticket for the next show. Let s look at just a few features of our solar system. sun info card Sun visible disk rotating Our sun, the star we live close to Ten times as wide as Jupiter, 109 times as wide as Earth, hydrogen and helium gas. 7

8 big spot in view BW sunspots Solar energy really comes from nuclear energy, released deep inside the sun, at the sun s core, where it s about 27 million degrees, far hotter than the surface. Temperature at the sun s surface, 10,000 degrees; inside a sunspot, not quite as hot. Swedish Vacuum Telescope sunspot size of Earth superimposed over Swedish sunspot view TRACE loops more TRACE loops Special telescopes show us beautiful loops of hot gases, much larger than the Earth, near the bright surface of the sun. Mercury title Mercury, the planet closest to the sun. Mariner 10 hemisphere zooming Mercury photo Mercury info card Mercury Caloris basin On the surface: craters, like those on our moon. A family of giant rings was made when a huge chunk of rock smashed into Mercury long ago. rings superimposed for about 2 sec. ridge & crater The ridge running through this crater tells geologists that Mercury shrank slightly a very long time ago. ridge and crater supers to 0114 Venus title Venus photo Venus info card Venus. With a regular camera, we see only clouds.. 8

9 disk: clouds super title clouds disk: radar with super title radar view but with a radar camera we can see the surface. flyover Venus has at least 1000 large volcanoes 1. None appear active. Tick crater in view 1st pancake Some volcanoes on Venus have a peculiar pancake shape. It seems that molten rock came up through openings in the surface and spread out on the ground. more pancakes Earth title Earth photo Venus has a thick atmosphere, made of carbon dioxide. The carbon dioxide atmosphere traps heat by the greenhouse effect, so Venus is hotter than Mercury 900 degrees, day and night. Earth info card Earth and Moon movie Inside ISS Susan Helms in view Susan floats away Window in view Earth, our home in the universe, and our companion, the moon. In the twentieth century we began to leave our home and travel into space. If you live on the International Space Station, 230 miles above Earth, you use networked computers to control the station and know where you are as you circle our planet. In orbit, you are weightless, so you can float wherever you want to go. And in your spare time, one of your favorite things to do is to look out the window

10 window fills screen Hurricane Katrina super title Hurricane Katrina August 2005 Earth's Moon title Moon photo Moon info card Moonwalkers big boulder fills screen second astronaut Mars title Mars photo Mars info card Mars rotating globe Mars limb with atmosphere Weather in our atmosphere is caused by solar energy striking the air, water and land. Sometimes Earth s weather can be dangerously powerful. Example: Hurricane Katrina, which blew across Mississippi and Louisiana in Now, compare Earth to our moon. What a difference! A giant rock in space, covered with dust, boulders and craters made when giant rocks smashed into the surface long ago. Today, nothing changes here. The last new thing to happen on the moon was more than 30 years ago, when Apollo astronauts landed on six different missions. So far, no astronauts have visited any other world beyond the moon. The moon has no air, no weather, so the sky is black even in the daytime. Astronauts had to wear space suits so they would have air to breathe. The moon has gravity, but it's weaker than ours. An astronaut in a moon suit weighs 360 pounds on Earth, but only 60 pounds on the moon. That s light enough to get around by hopping! Mars: only half the size of Earth, but fascinating. Rotation: 24 hours 37 minutes. There's a polar cap of frozen carbon dioxide during Martian winter. 10

11 Gorgonum crater Atmosphere? Only a little, and it s carbon dioxide, which our bodies cannot use. When we look straight down into some craters and canyons on Mars we see gullies. On Earth, gullies are made by erosion when water flows downhill. gullies super title to 0436 Eagle crater pan bounce marks in view Dells zoom in fades to black Deimos, Phobos, Gaspra comparison Phobos photo Moons of Mars info card Asteroid Eros title Eros photo Yet we have never found liquid water on Mars only ice. In 2004, two rovers, named Spirit and Opportunity, landed on Mars. Rover Opportunity came down in the bottom of a small crater. Rocks in the crater wall were very interesting. On its 41st sol, or Martian day, Opportunity took a closeup picture of a rock we call the Upper Dells. Important discovery: curved rock layers, formed long ago in a salty sea. There WAS liquid water on Mars. But we still don t know when, for how long, or what happened to it. Mars has two moons, Deimos and Phobos, much smaller than our moon, about the same size as the asteroid Gaspra, which is about 10 miles long. Maybe Deimos and Phobos used to be asteroids, before they were somehow captured by the gravity of Mars. Eros info card NEAR Eros movie Itokawa There are thousands of asteroids in our solar system. Space probes have visited only a few. Asteroid Eros is about 21 miles long and covered with craters. 11

12 Comet Halley title Halley photo Asteroid Itokawa is only 1700 feet long. A Japanese space probe took these pictures. Halley info card Halley Giotto movie Deep Impact and Comet Tempel 1 Comet Halley. In 1986, a space probe flew right into the head of Comet Halley to show us the giant dirty snowball, called the nucleus, that makes the gases and dust in the comet s tail. July 4, 2005: the Deep Impact probe meets Comet Tempel 1 on purpose. The probe took pictures as it smashed into the comet at 23,000 miles per hour. Why? To dig up material from inside the comet to find out what its ingredients are. Jupiter title Jup rotation movie Jupiter photo Jupiter rotates faster than any other planet in our solar system: once every 9 hours 50 minutes. Temperature: minus 160 at the cloud tops, where winds blow 300 miles per hour. Jupiter info card Jupiter GRS Cassini movie Jupiter's Great Red Spot: a storm at least 400 years old. Winds go around the spot every six days. Io title Io photo Io info card Io: one of Jupiter s four largest moons. Io crescent super title erupting volcanoes Io s special feature: erupting volcanoes, spraying melted sulfur and melted rock onto the surface like a paint gun. Result: a constantly changing surface of yellow, orange, red, black and white. 12

13 Io slow pan over surface Europa title Io. Jupiter s moon Europa: once thought to be boring compared to pan over dark fractures But not any more not since the Galileo space probe sent us close-up pictures of dark fractures and mysterious ridges and grooves in Europa's icy surface. fly over light ridges In some places, the ice seems to be broken into pieces that have moved and twisted, like puzzle pieces coming apart. Could these be icebergs floating on water or slush, like icebergs on Earth? Could Europa have an ocean under the ice? To find out, we need to send more probes. Europa photo Europa info card Ganymede title Jupiter s moon Ganymede: our solar system s largest moon, with a surface of ice covered by dark dust. Ganymede photo Ganymede info card disk rotating diss. To fly-over ridges Callisto title Callisto photo Callisto info card Callisto disk zooming pan over gray mts with white peaks Long, straight grooves in the ice: a major feature of Ganymede. How did these grooves and ridges come to be? That s an unsolved mystery. Jupiter s moon Callisto: more craters per square kilometer than any other moon we know in our solar system. 13

14 Saturn title Saturn photo Close-up views show white mountain peaks that may have been left by dark dust slowly sliding downhill over the icy surface. Saturn info card Saturn rotating globe Saturn changing ring angle Saturn Voyager departure movie Saturn: even without its rings much larger than Earth, almost as big as Jupiter. We see the rings at different angles at different times during Saturn s year. One year on Saturn equals 29 years 5 months on Earth. Saturn s rings are not solid. They re actually millions of chunks of ice and dirt, orbiting Saturn like tiny moons. Cassini pink rings Cassini scalloped rings straw texture Shepherd moons and F ring Our closest pictures of Saturn s rings were sent to us by the Cassini space probe in July The streams of particles make amazing, beautiful waves and spirals in the rings. Watch carefully: two tiny moons make waves in one of Saturn s thinnest rings with their gravitational pull. Titan title Titan photo Titan info card Titan orange fuzzball haze on crescent Cassini BW rotation movie Titan, Saturn s largest moon is the only moon in our solar system with an atmosphere. Regular cameras see only orange haze, hiding everything on Titan. 14

15 Cassini Oct 04 approach movie Cassini July 04 closeup with clouds super title clouds pan up along picture Titan drainage channels Iapetus title Iapetus flyby movie Uranus title Uranus photo Uranus info card Uranus & moons & rings movie Miranda title Miranda photo But the Cassini space probe has cameras that can see through the haze, at least a little bit. Titan s atmosphere is mostly nitrogen. Cassini saw some lightcolored clouds moving in Titan s atmosphere. Other light and dark areas look like clouds, but they re not; they are the colors of the surface. On January 14, 2005, 2 a European probe called Huygens, which was carried to Saturn by the Cassini spacecraft, went down through Titan s clouds on a parachute. Huygens photographed dark lines on Titan that look like gullies. But they could not have been made by water, because the temperature is 300 degrees below zero. The only substance on Titan that could be liquid is liquid natural gas. Huygens landed on Titan and photographed rocks, which are probably made of ice. Iapetus, one of Saturn s smallest moons: also one of the oddest moons we know. The side of Iapetus that faces forward as it goes around its orbit is almost black; the other side, almost white. Uranus: this fast-forward movie shows Uranus s rings and some of its moons. Uranus spins on its side, so there are times when the sun shines straight down on its north or south pole. The only other planet that does that is Pluto

16 Miranda info card Miranda: Miranda disk, slow zoom toward cliffs dissolve to c/u cliff region super callout cliffs to 1050 Neptune title Neptune photo Neptune info card big disk with Great Dark Spot super title 1989 a tiny but amazing moon of Uranus. 3 Look carefully for ice cliffs at least 3 miles high, higher than the walls of our Grand Canyon. Neptune. cut to 1994 HST disks with title 1994 Triton title Triton photo It had a Great Dark Spot in its atmosphere when the Voyager 2 probe flew by in But in 1994, the Hubble Space Telescope checked again. The Great Dark Spot was gone! So weather does change, even on this extremely cold planet. Triton info card Triton zoom-in streaks prominent Triton, Neptune s largest moon. Dark streaks might have been made by winds in the extremely thin nitrogen atmosphere. Some areas look a little bit like the skin of a cantaloupe melon, even though they are made of ice. Since Triton is about the same size as Pluto, and almost as far from the sun as Pluto, some astronomers think Triton may be giving us a preview of Pluto, something like what will see when the first space probe get there

17 cantaloupe prominent Pluto and Charon title Pluto photo Pluto info card HST two dots, zooming out Pluto, the ninth planet. title 2003 UB 313 (A Kuiper Belt object) Or, the largest known object in the KUIPER BELT, named after the astronomer Gerard Kuiper. The Kuiper Belt is a swarm of small icy objects we're discovering beyond the orbit of Neptune over 800 are known so far 4. Pluto is the only planet no spacecraft has ever visited. A picture from the Hubble Space Telescope shows Pluto and its moon Charon, both smaller than our own moon UB 313: one of the most recently discovered Kuiper Belt objects. Even with a giant telescope and a super digital camera, it s just a dot. But the way it moves tells us it s not a star, but something going around our sun. This object may be larger than Pluto, possibly the tenth planet UB 313 discovery sequence, 3 frames looped title Sedna Sedna, discovered November This tiny world is too far out to be part of the Kuiper Belt. It s three times farther out than Pluto and takes 10,500 years to go once around the sun. 5 It may be part of a giant, far-out, unseen cloud of comets called the Oort Cloud, named after the astronomer Jan Oort. discovery loop fades black Planet line-up The nine planets, plus a few other things, drawn together so we can compare sizes. Earth is one of the smaller planets, along with Mercury, Venus and Mars. You can see the main asteroid belt, then the giant

18 planets Jupiter, Saturn, Uranus and Neptune. By the way, Jupiter, Uranus and Neptune also have rings, but they are very thin and made of dark dust particles, so only a special telescope can see them. Beyond Neptune, there's Pluto and the Kuiper Belt. Planet size module Back at school, you can make your own drawings or charts to compare planet sizes. End of Planet size module This picture shows only planets, no moons. Here s a question for you to explore: using the internet or a good book, look up the sizes of the largest moons of Jupiter and Saturn, and the sizes of the smallest planets. Make a chart or a scale drawing to answer this question: Is it true that all moons are smaller than all planets? You can find out for yourself. Planet interior module What s inside planets? We have no way to go deep inside planets to find out, but we have other clues. Here s what we think so far. If we could cut open Mercury, Venus, Earth and Mars, we think we d see a core, make mostly of iron and nickel; then a mantle, made of rock that s so hot it can move slowly; then a thin crust of solid rock that makes the surface; then, for Venus, Earth, and Mars, above the surface, an atmosphere. Jupiter, Saturn, Uranus and Neptune: much larger and very different. Take Jupiter for example. A small core of rock and possibly ice, then a thick layer of hydrogen, squeezed into a bizarre liquid form, then an atmosphere thousands of miles thick, then a layer of colored clouds that we see with our telescopes. You could not land or walk on Jupiter: there s no solid surface! Saturn: similar to Jupiter. Uranus and Neptune a core and a very deep atmosphere, but no layer of liquid hydrogen. Here s a very interesting case we re not sure about yet: Jupiter s moon Europa. It might have a core of metal, then a mantle of rock, and then possibly a layer of water, with an ice crust and a liquid ocean below. We re not sure yet. 18

19 End of planet interior module Mars, Caholia pan We have learned a lot so far in the exploration of our solar system, but there s more to come in the future. Let s look at some UNSOLVED MYSTERIES. pale orange sky On Mars, in the Columbia Hills. This actual photograph was taken by the Mars Exploration Rover Spirit in August 2004, and specially adapted to show you here in the Planetarium. A few minutes ago, we saw pictures taken by a space probe looking straight down into a crater, and we saw gullies. Then we saw a picture of a rock with curved layers that formed in a salty sea long ago. But we still don t know when Mars had seas, or what happened to them. And if Mars had liquid water, did it ever have life? At this time, we do not know. Maybe, when you get older, you will help us find out. Europa ice ceiling Under the ice on Jupiter's moon Europa. Actually, we don't know what's under the ice, so we are using our imagination combined with the best clues we have so far. Sound effect for probe punching through Pluto-Charon scene with distant sun And there's a possible future probe from Earth, punching through the ice and launching a little R.O.V., like the one you can see next door at the museum, to explore the water if there IS water under the ice on Jupiter's moon Europa. Remember Jupiter's moon Europa? You saw pictures from one of our space probes that show big chunks of ice that look like icebergs. If they are icebergs, are they floating on water? If so, what is in the water, if anything? Could it be that Earth is not the only world in our solar system with an ocean of liquid water? At this time, we do not know. Maybe, when you get older, you will help us find out. Welcome to high noon on Pluto. That's the sun, four billion miles away. Pluto's moon Charon looks huge in the sky, because we know Charon is close to Pluto compared to its size. 19

20 Pluto is the only planet in our solar system that no space probe has ever visited, so we don't really know much about what it's like. We know it must be very cold, about 390 degrees below zero. It may have a very thin atmosphere, but not for long. Right now, Pluto is in the part of its orbit closest to the sun. But as Pluto revolves around its 248-year orbit it will slowly get farther away. That means it will get even colder. Pluto experts think that in about 20 Earth-years from now, Pluto's atmosphere will freeze solid on the ground and remain frozen for the next 200 years. A space probe called New Horizons was launched toward Pluto January 19, It will reach Pluto in Our final unsolved mystery for today: how many OTHER solar systems are out there in space? Remember when we go outside and look at the night sky, every star we see is another sun. Our most powerful telescopes cannot yet see planets going around other stars. But we have clues. For instance: in our neighborhood in the universe, astronomers so far have found about 100 wobbly stars. These stars move back and forth very slightly every few months, exactly as we'd expect if they had planets going around them, pulling on them with their gravity. We still cannot see the planets, just their gravitational tug on their parent stars, but we re pretty sure the planets are there. HST photo of protoplanetary disk-jet system HST view of Kepler telescope rural landscape Here s another kind of clue. These real pictures from the Hubble Space Telescope show glowing, swirling clouds of dust around stars. Maybe, in the future, these dust clouds will turn into systems of planets. Other space telescopes of the near future will look for other clues. For example, the Kepler telescope, to be launched in 2006, will look for ever-so-slight dips in the brightness of stars, caused by their own planets passing in front of them. Think of the wonderful variety of planets and moons just in our own solar system. Who knows what amazing things wait for us in OTHER solar systems? But, for now, let's go home, to the beautiful skies of western New York, and find out how YOU can see the planets in your REAL sky. 20

21 OPERATOR: live sky tour Sunrise music and effects Twilight. The end of night. A new day is beginning. We'll get busy with our world, but we'll remember the mysteries waiting out in space. What happened to the water on Mars? What's under the ice on Europa? What is Pluto really like? These are some of the greatest unsolved mysteries of the solar system, our home in space. If you're one of the younger people in the audience, maybe one of these mysteries will be solved by you. 21