Celestia Student Lab pg 8
Exploring the Solar System
PART A - THE SUN and SOLAR NEIGHBORHOOD
1. Let’s begin our tour of our solar system by opening Celestia. Go to Start, Programs, Celestia and click to open. The program will open with a dramatic scene of space.
2. Click on the word, “Render” and select View Options. A new box will open. Put a check in the following boxes: Atmospheres, Clouds, Eclipse Shadows, Galaxies, Night Side Lights, Planets, Stars, Stars as Points. In the lower boxes, the box labeled “Terse” should be checked. All other boxes should be unchecked. Click OK to close the box.
3. Click on the word, “Render” again and make sure Ambient Light, None and More Stars Visible are selected. To get the maximum number of stars the program will display, just hit the “]” (bracket) key on the keyboard several times.
4. Let’s start with our own sun. Let’s get close. On the toolbar, choose the Navigation tool and Select Sol. (Sol is the “official” name for the sun). Now, type a “G” key on the computer (G means Go to).
5. Zoom in on the sun by pressing the “Home” key on the keyboard several times. Home always zooms in. Press End to zoom out. Zoom in on the sun until at least 2/3 of the sun fills the screen. Fortunately for us, this is a computer program. If we were ever in a spaceship and got this close to the sun, our ship would melt and the gamma and x-rays would kill us in a matter of seconds, even inside our spacecraft.
6. Look in the upper right corner of the image and you’ll see today’s date and under it, the words, “Real Time”. That means everything on the screen is moving and rotating at their actual speeds. Since the planets move slowly, we’d be here all day watching the screen unless we can speed things up. To do so, on the keyboard, type the letter “L”. You’ll notice the display in the upper right corner has changed to read, “10X faster. Type L again and it becomes 100 x faster. Keep hitting L and the time clock keeps speeding up. To slow time down, type the letter “K”. Now, set the time to about 100,000 x faster. Record the approximate number of sunspots you see on the enclosed Data record (see back of this file) in space # 7 (the “7” corresponds to this paragraph number). Don’t speed too much time on it.
7. In the upper left corner of the screen is another text display. Here, you’ll find the distance you are from the object, its Absolute and (Apparent) magnitudes, its temperature, and if it’s a star, its spectral class. In the data record, record the sun’s Absolute Magnitude, its temperature and its spectral class in the spaces provided.
8. . Now, to get our spaceship moving, press the “A” key on the keyboard. Notice that our speed, displayed in the lower left corner of the screen, has now begun to increase. Every time you press the “A” key, the speed increases a bit more. To slow down, press the “Z” key. Got that? “A” to speed up and “Z” to slow down. To stop completely, press the “S” key. Set the speed so it reads between 16 and 17 km/s. That is the fastest speed our fastest spacecraft has ever traveled. It’s equal to the incredible speed of 40,000 miles/hr. To reverse course, type the letter “Q” on the keyboard. Let’s speed up again, to the fastest speed ever traveled by ANYTHING in the universe … namely, the speed of light (abbreviated “C”). It is a whopping 186,000 miles/sec, or 670 million miles/hr. The speed display in the lower left of your screen will say “1.00 C”.
9. OK, let’s move on. Press the “S” key. This will stop your spaceship. Then press the Esc key in the top left corner of the keyboard. This will break our lock on the sun, allowing us to travel freely though the stars. Now, let’s locate Mercury. Click on the Navigation tool on the top of the program, and choose Solar System Browser. Select Mercury and click the tab marked “Center”. Click OK. Right click on it and select “Follow”. This will lock us onto Mercury. Now, move your mouse to move around, and use the “Home” and “End” keys to zoom in and out
10. Press the “V” key once to increase the information on the display and complete the data in the data record marked # 13. To find out the number of Mercury’s moons (IF ANY), right-click on the planet
11. OK, on to hot and acidic Venus. Check for its moons (if any), and Complete the data record as # 14.
12. Our own Earth is next. Select Earth from the Navigation toolbar choose “Go to”, and click OK. Our beautiful home planet will zoom into view. What a sight. Right click and moving the mouse, move around Earth, looking at it from all sides, including its top and bottom poles and ice caps. This program is sooo cool that on the night side, you’ll see the lights from Earth’s cities all lit up. That is actually what Earth looks like from space. This view is about as accurate as it can get. Rotate Earth so that the Milky Way is in the background. What a lonely place we occupy in space … so far away from even the next star.
13. What is it like to actually fly above Earth in orbit? Is it lonely? What if we could fly anywhere, soaring high above the planet or swooping down through its atmosphere and even under its clouds to skim above its oceans in our own space cruiser? With Celestia, we can! Get ready for the trip of a lifetime. You ready?
14. With your right mouse, move the planet so you’re on the sunny side of the planet somewhere above the ocean. Now, tap the Home or End key several times until your altitude above Earth is about 7,000 km (just get close). Its time to fire our engines. Press the “A” key to begin accelerating toward Earth until your speed is about 18 km/s. Earth will begin to drift closer. Now, we’re going to use four new keys for the first time. On the keyboard, locate the UP arrow, DOWN arrow, and Left and Right Arrows. Tap the Left arrow once. Notice that your ship rotated and banked in space. Tap the Right arrow. It rotates the other way. Tap the UP arrow key. Your ship moves upward. The DOWN arrow key moves the ship downward. Using these keys, position the Earth so that its western edge is at the top of the screen. See the picture below.
15. You see an actual hazy atmosphere just clinging to its edge? It is so very thin and fragile. That is how thick our atmosphere is … not much more than a thin band protecting us from the cold and hostility of space.
16. Fly down and down until you’re no more than 500 km above the planet’s surface. What a view! Now, begin to level off, using the UP arrow key. Your altitude should be dropping no more than about 2 km/sec. Adjust your angle until you’re coasting just above the atmosphere.
17. Let’s visit a famous spacecraft. Select the Navigation toolbar, Solar System Browser, and click the (+) next to the word Earth. A list of its satellites will appear. Select MIR and press Go to. If MIR is in darkness, press the “L” key to speed up the time until daylight appears, then press the “K” key to return to Real time. Once MIR is centered, right-click on it and rotate around, looking at it and the Earth below from all angles. Mir was a Russian space station that spent over 20 years in space. Men and women worked and lived in it for months at a time, orbiting the Earth just as you are doing now.
18. Complete the data record for Earth as # 28.
19. On to the Moon. Select the Moon as a satellite of Earth from the Navigation toolbar and go there. Zoom in further with the Home Key
20. OK, next stop is Mars. Select Mars from the Navigation Toolbar and go there.
21. Notice that Mars has an atmosphere which you can see if you look at the planet edge on (zoom in with the Home and End keys and the arrow keys). It’s mostly carbon dioxide. It also has wispy clouds here and there. They are made of ice particles. Mars does have two natural moons. They are small football shaped rocks called Phobos and Deimos. Quickly visit one of them by selecting them from the Navigation toolbar, clicking the (+) around Mars. Go there. Take a look. Not much to speak about as moons go but there you are.
22. Complete the Data record for Mars as step 34.
23. Our last stop in the inner solar system is the Asteroid belt. This is the place where the asteroid that hit Earth and killed the dinosaurs probably came from. There are billions of asteroids (space rocks). Let’s visit two of the biggest ones. In the Navigation toolbar, select Solar System Browser and below the listing of Pluto, you’ll locate Gaspra. Then, go visit the asteroid Ida (scroll down the list a bit). Ida is a much bigger asteroid (over 30 miles wide) and is unique in that it has its own tiny moon. Look for it near Ida. If Ida ever hit Earth, all life on the planet might be snuffed out (a true mass extinction).
24. Complete the data record for Ida as step 36.
End of Part 1.
Part 2 – the Outer Solar system
25. Launch Celestia using Start, Programs and Celestia
26. Hit the “L” key to speed up the time to 100 X. Jupiter will begin turning under you. Now, look closely. The cloud bands drifting around the planet are actually moving at different speeds, just like in real life (this program just kills me!). If you can’t notice it, speed up to 1000 X. The swirling clouds will become noticeable. As you watch, tiny moons and the shadow of moons will also pass Jupiter’s face. You’ll also notice its mighty Great Red Spot. The Red spot is a huge hurricane type of storm that has been raging for over 300 years in that same spot. No one knows how it formed or why it keeps on blowing at over 1,400 mph. However, it is HUGE. The entire Earth would fit inside it with room to spare. It doesn’t rain in it, but there are lots of huge lightning bolts in the Red Spot, and all over Jupiter.
27. Let’s set up a great flyby of Jupiter. Reduce the time to 10 X with the “K” key. With the left mouse button, move and drag Jupiter so that you could just skim by it if you were to fly straight ahead. Now, press the “A” key to start our spaceship going. Adjust the speed to about 1400 km/s (which is 100 times faster than our fastest spacecraft) and you’ll begin flying along Jupiter’s edge. To adjust your direction, press the “4” or the “6” on the number keyboard (right side of keyboard) and your ship will turn left or right. Try to just fly through Jupiter’s atmosphere, without crashing into the planet. It’s WILD!
28. up in his house for 15 years, until he finally died. Enjoy this view. Galileo eventually died for it!
29. Use the “K” key to slow time back down and complete the data record for Jupiter as step 41.
30. Using the Navigation tool, select Solar System Browser, click the (+) next to Jupiter and select “Callisto. Choose Go to. Callisto is an average sized moon but it is full of craters. It has more craters than any other moon in the solar system.
31. Complete the data record for Jupiter’s four big moons as step 46.
32. Let’s go to Saturn. Let’s fly there. Using the Navigation tool, select Solar System Browser, click on Saturn and select “Center. Saturn will become centered, far away from Jupiter. Press the “A” key and speed up to about 40 C (40 times the speed of light). In “Star Wars”® talk, we have jumped to hyperspeed. Watch the altitude display in the upper left corner. It will be dropping rapidly in AU. When the distance from Saturn approaches about 0.5 AU, hold down the “Z” key and SLOW down fast. Using both keys, jump out of hyperspeed and drift to within about 400,000 km of Saturn. Hit the “S” key to stop your ship.
33. Record its name and radius in the data record as step 49b.
34. Lastly, zoom way out from Saturn until its outermost large moon is visible. Record the moon’s name in the Data Record. It’s quite a long away from its outer moons to the planet, isn’t it?
35. On to Uranus. Using the Navigation tool, select Solar System Browser, click on Uranus and select “Go to. In the Data record, describe Uranus’ three noticeable features, as the questions ask (step 52).
36. We end our solar system tour with a visit to Pluto and Charon. Using the Navigation tool, select Solar System Browser, click on Pluto and select “Go to. Pluto will zoom into view. Turn the view and you will also see Charon. Its moon is more than half as big as Pluto. Many Astronomers believe both Pluto and Charon are very large comets that were captured into their current orbits by the gravity of the sun billions of years ago, and should not be called planets or moons at all. However they formed, Pluto and Charon both are very much like comets. They are giant balls of frozen rock and water ice, orbiting the sun far away from its warmth. Zoom in on Pluto and you can see some of its ice cracks and craters. Swing Pluto around so you are at its dark side and locate the sun. It’s just a tiny dot so far away.
37. No spacecraft has yet visited or photographed Pluto or Charon. Voyagers 1 and 2 are way beyond Pluto’s orbit, but when they flew past, Pluto was not nearby, so we could not take any pictures of it. All our images come from fuzzy pictures taken by the Hubble Space telescope. The image you see is our best estimates of Pluto’s surface and color.
A journey to the Stars
38. The nearest star to you and our sun is Rigel Kentaurus A and its mates, Rigel Kentaurus B and Proxima Centauri. These 3 stars orbit each other. Look around you. Where, in that vastness of space, are they?
39. Let’s visit one of them. Remember, at the speed of 40,000 mph, our fastest spacecraft, it would take you over 76,000 years to reach just the nearest star. Because we don’t have that kind of time, we are going back into hyperspeed and make a jump. First, uncheck the orbits box by returning to the Render menu. Then, using the Navigation tool, select Star Browser, click on Proxima and select “Go to. Our sun will zoom away and one of those small stars in the background will zoom in. What do you immediately notice about our nearest neighbor? Looks like a Red Giant, doesn’t it? Zoom in to get a real close look. Hit the “V” key to bring up 6 lines of text about this star. From that information, including its radius, temperature and its spectral class, what kind of star is Proxima Centauri? Complete the information in the Data record as step 59.