AST 113 ASTRONOMY Lab 6

Lab 6  Question 1 1 out of 1 points Lab 6 Figure 1 - Click Image to Enlarge Finding Venus We will start this lab by finding the planet Venus. In this lab, you will use the Starry Night software to lear ...

Lab 6  Question 1 1 out of 1 points Lab 6 Figure 1 - Click Image to Enlarge Finding Venus We will start this lab by finding the planet Venus. In this lab, you will use the Starry Night software to learn about and answer Questions related to Venus. You should have a general familiarity withStarry Night before attempting this portion of the lab. To become more familiar with Starry Night, access the tutorial exercise within the software. Begin this activity at 11:00 a.m. on June 1, 2014. To do this, enter the date and time in the Time and Date field. Make sure that your location is set to Phoenix, Arizona. Next, look toward the west by clicking the W viewing direction button located on the button bar across the top of your screen, or by pressing the letter W on the keyboard. The screen will pan toward the west. Right-click in the viewing pane and select Hide Daylight from the list. This action allows you to better see the stars and planets. Next, click the Constellations button to show the constellations. After you have had a chance to explore.Lab 6 Figure 2 - Click Image to Enlarge Finding Venus (cont.) Click the Find tab. A list of planets should appear. Those that are highlighted are currently up in your evening sky. Those that are not highlighted are not up in the sky at this time. We want to find the planet Venus. Double-click or right-click it (Control-click for Mac) and select Centre. This action pans the screen and centers Venus. You can now zoom in on Venus either by using the Zoom controlat the far right of the control panel or by right-clicking (Control-clicking for Mac) Venus on the Find tab and selecting Magnify. Click the information icon (i) next to Venus on the Find tab to read a short description of the planet Venus. Next, select the Info tab on the left side pane and click the (+) sign (gray arrow for Mac) to expand each of the information categories. Note that Venus will exhibit phases depending on the position of the Sun and our viewing angle from Earth. Use the information on the Info tab to answer the Questions on this screen. After you have had a chance to explore, use the Starry Night software to answer these Questions, making sure that your date and time are still set to June 1, 2014, at 11:00 a.m. and that your location is Phoenix. What is the radius of Venus?  Question 2 1 out of 1 points Given that Earth’s radius is 6378 km, what percentage of Earth’s radius is Venus’s radius?  Question 3 1 out of 1 points What is the mass of Venus in relation to Earth?  Question 4 1 out of 1 points What is the angular size of Venus as seen from Earth? Selected Answer: 14.0 arcseconds Correct Answer: 14.0 arcseconds  Question 5 1 out of 1 pointsWhat is Venus’s orbit size?  Question 6 1 out of 1 points What is the length of a sidereal day for Venus?  Question 7 1 out of 1 points What is the length of a solar day for Venus?  Question 8 1 out of 1 points How long is a year on Venus? Question 9 1 out of 1 points In which constellation is Venus currently?  Question 10 1 out of 1 points What is Venus’s current apparent magnitude?  Question 11 1 out of 1 points How far is Venus currently from Earth?  Question 12 1 out of 1 points The distance at inferior conjunction (closest to Earth) is calculated by subtracting the planet’s orbit size from Earth’s distance from the sun (1 au). What is Venus’s distance at inferior conjunction?  Question 13 1 out of 1 points The distance at superior conjunction (farthest from Earth) is calculated by adding the planet’s orbit size to Earth’s distance from the sun (1 au). What is Venus’s distance at superior conjunction?  Question 14 1 out of 1 points Lab 6 Figure 3 - Click Image to Enlarge Venus's Orbital Characteristics Next we will use the Starry Night software to observe the characteristics of Venus's orbit. Use the Zoom control at the farright of the control panel to zoom back out to full-scale view. Right-click (Control-click for Mac) on Venus and select Orbit. This action shows Venus's orbital path as seen from Earth. Notice that you can only see a portion of Venus's orbit because part of it is blocked by the horizon. Click the Horizon button on the button bar to hide Earth's horizon for a complete view of Venus's orbit. Also click the Daylight button to turn off daylight. You should still be locked on to Venus. If not, right-click (Controlclick for Mac) the planet Venus and select Centre. To maintain the proper perspective, select Ecliptic Guides from the View menu and select The Ecliptic. Next, select 1 days from the Time Flow Rate drop-down list and click the Play time mode button. If you need to slow down or speed up, adjust the Time Flow Rate field as needed. You should be able to see Venus locked in the center of your field of view as it moves across the starry background. The planet should complete a full revolution in less than a minute. For inferior planets like Mercury and Venus, you can lock on the Sun for best results. Right-click (Control-click for Mac) on the Sun and select Centre. For an inferior planet such as Venus, determine the greatest elongation and the dates of greatest elongation both for morning observing and evening observing. The greatest elongation is the angle between the Sun and the planet, as seen from Earth. To find this value, hover the pointer over the Sun until it changes from a hand to an arrow; then click the pointer at the center of the Sun, hold the mouse button, and drag the pointer to the farthest orbital extension. If you have trouble with this, click the tool selection icon at the upper left of the control panel and select Angular Separation. Reset the tool selection to Adaptive when you have finished. To determine the dates of greatest elongation, reset the date to June 1, 2014, and click the Sunset button. You might find it helpful to step forward and backward one day at a time until you have placed Venus at its farthest extension in orbit relative to the Sun. After you have had a chance to explore, use the Starry Night software to answer these Questions. Moving time forward from June 1, 2014, what is the angle of the next greatest elongation of Venus?  Question 15 1 out of 1 points What is the date of the next occurrence (after June 1, 2014) of greatest elongation of Venus?  Question 16 1 out of 1 points What is the date of the following occurrence (after the date of your previous answer) of greatest elongation of Venus?  Question 17 1 out of 1 points To answer this Question, you will need to view the position of Venus as seen from outer space and compared to the positions of the other planets. To do so, select Planets from the Favourites menu and click Inner Planets, then click Inner Solar System. On June 1, 2014, which object appears closest to Venus?  Question 18 1 out of 1 points On October 25, 2015, which object appears closest to Venus?  Question 19 1 out of 1 points Lab 6 Figure 4 - Click Image to Enlarge Flying to Venus: Solar and Sidereal Days Let's see what a day (technically referred to as a solar day) would be like on Venus. The easiest way to experience a solar day is to watch a sunset, take note of the date and time, then watch another consecutive sunset, and determine the time difference between them. For the purposes of this exercise, make sure that the date is set to June 1, 2014, and that you turn off planet labels and orbital tracks using the Find side pane.Right-click (Control-click for Mac) Venus and select Go There from the menu. (Note: You can animate the journey by first deselecting the Only animate intra planet changes box under File/Preferences/Responsiveness. Also be sure to have your horizon turned on to see the photorealistic surface panorama.) View the surface of Venus by selecting Other from the Viewing Location drop-down menu, then select The Surface of, Venus from the View From drop-down menu. Click the E viewing directionbutton on the button bar or press the E key on the keyboard (because Venus rotates in retrograde, sunset will be to the east). Next, select 1 days from the Time Flow Rate dropdown list. Click thePlay time mode button. When the Sun is near setting, click the Stop button. Use the Step Forward and Step Backward time mode buttons until you see the Sun just starting to set. You might then want to select a smaller unit of time until the Sun is just touching the horizon. Note the date and time. Continue to the next sunset and record the date and time. Calculate the time difference between the two sunsets. This difference is the length of a solar day on Venus. Record this information (you will need it to answer the Questions on the next screen). The solar day is not the same as the sidereal rotation period of the planet. This is because the solar day takes into account both the rotation of the planet and the revolution of the planet around the Sun. Your calculation of a solar day can now be compared to the sidereal day found from the Info tab earlier in this activity. After you have had a chance to explore. Lab 6 Figure 5 - Click Image to EnlargeFlying to Venus: The Planet's "Year" To determine the revolutionary period, or the planet's "year," return to the solar system view. Point to Solar System on the Favourites menu and click Inner Solar System. Select 1 Days from theTime Flow Rate drop-down list (or something slightly slower), click the Play button, and then note the time it takes for the planet to return to its original position. You might find it easiest to align the planet to the furthest left or right before starting. Write down your observation (you will need it to answer the Questions on this screen). After you have had a chance to explore, use the Starry Night software to answer these Questions. What is the length of a solar day on Venus?  Question 20 1 out of 1 points What is the length of a sidereal day on Venus?  Question 21 1 out of 1 points To find the percentage difference between a sidereal day and a solar day on Venus, take the difference between a sidereal day and a solar day and divide it by the length of a sidereal day thenmultiply that number by 100 to convert to a percent. What is the percentage difference between a sidereal day and a solar day on Venus?  Question 22 1 out of 1 points How long is a year on Venus?  Question 23 1 out of 1 points Lab 6 Figure 6Energy, Absorption, and Reflection We now move our discussion from the planet Venus to the topic of greenhouse gasses. This section of this lab is about energy, absorption, and reflection. Objects give off different amounts of light depending on their temperature. Figure 6 shows the energy output of our Sun along with the percent of energy given off by the Sun in the ultraviolet (UV), visible (VIS), and infrared (IR) portions of the electromagnetic spectrum. Lab 6 Figure 7 - Click Image to Enlarge Energy, Absorption, and Reflection (cont.) Earth's surface temperature is affected by light that is absorbed at the surface. A photon's ability to travel through our atmosphere depends on its wavelength. Figure 7 shows that some wavelengths of light are absorbed in our atmosphere more than others. The figure also lists the primary gas molecules responsible for absorbing the different wavelengths of light. Molecules that are transparent to visible light but absorb and reemit infrared light are known as greenhouse gases. After visible light from the Sun reaches the surface of Earth, some of the light is reflected back toward space as visible light; the remaining light is absorbed by the ground. Reflected light does not change the temperature of the surface, whereas absorbed light causes the temperature of the surface to increase. Earth's heated surface then gives off infrared light to Earth's atmosphere. As an example, on a hot day, black asphalt absorbs more visible light and gives off more infrared light than does a whitecrosswalk. Which two forms of light account for the majority of energy coming from the sun?  Question 24 1 out of 1 points Which type of light has the easiest time getting through our atmosphere?  Question 25 1 out of 1 points Which type of light experiences the most absorption?  Question 26 1 out of 1 points Why is ultraviolet light NOT an important energy source for heating the surface of Earth?  Question 27 1 out of 1 points Which gas molecules are primarily responsible for the absorption of ultraviolet light?  Question 28 1 out of 1 points Which gas molecules are primarily responsible for the absorption of visible light?  Question 29 1 out of 1 points Which gas molecules are primarily responsible for the absorption of infrared light?  Question 30 1 out of 1 points What are the two greenhouse gases most responsible for absorbing infrared light in Earth’s atmosphere?  Question 31 1 out of 1 points The Sun is approximately 6000° K at the surface and has an energy distribution that peaks at visible wavelengths. Earth’s surface is much cooler at about 288° K. What type of light does Earth’s surface primarily give off?  Question 32 1 out of 1 points Does Earth’s surface give off light at night and, if so, what type?  Question 331 out of 1 points What is the total amount of energy coming from the Sun (in watts per square meter)?  Question 34 1 out of 1 points Lab 6 Figure 8 - Click Image to EnlargeLab 6 Figure 9 - Click Image to Enlarge The Greenhouse Effect Figure 8 shows how light/energy flows through the Earth system for the "greenhouse effect." The numbers listed describe the amount of energy flowing through the system (in units of watts per square meter). A larger number indicates that more energy is flowing through that labeled pathway. Use Figures 8 and 9 when answering the Questions. What is the total amount of energy emitted and reflected by Earth to space (in watts per square meter)?  Question 35 0 out of 1 points How is the total amount of energy emitted by Earth to spacerelated to the total amount of energy coming from the Sun?  Question 36 1 out of 1 points What type of light primarily heats the Earth’s surface?  Question 37 1 out of 1 points What type of light primarily heats the Earth’s atmosphere?  Question 38 1 out of 1 points Is more energy absorbed by Earth’s surface in the form of light coming from the Sun or light emitted by Earth’s atmosphere? atmosphere Question 39 1 out of 1 points Because of the light absorbed by Earth’s surface that was emitted by Earth’s atmosphere, Earth’s temperature is cooler than it would be without this absorbed light.  Question 40 1 out of 1 points In Figure 9, the labeled boxes 9A through 9H represent various types of light. Which box(es) represent infrared light?  Question 41 1 out of 1 points In Figure 9, the labeled boxes 9A through 9H represent various types of light. Which box(es) represent ultraviolet light?  Question 42 1 out of 1 points In Figure 9, the labeled boxes 9A through 9H represent various types of light. Which box(es) represent visible light?