Observing Projects
Use the Starry Night™ program to view Earth from space. Click the Home button in the toolbar to move your viewing location to your home town or city. Click the Increase current elevation button beneath the Viewing Location panel in the toolbar to raise your position to about 11,000 km above your home location. Use the hand tool to move Earth into the center of the view. Locate the position of your home and zoom in on it, using the Zoom tool on the right of the toolbar to set the field of view to about 16° × 11°. Use the location scroller to move over various regions of Earth’s surface. (a) Can you see any evidence of the presence of life or of man-made objects? (b) Right-click on Earth (Ctrl-click on a Mac) and select Google Maps from the contextual menu to examine regions of Earth in great detail on these images from an orbiting satellite. (You will need to have access to the Internet in order to use Google Maps.) You can attempt to locate your own home on these maps. As an exercise, find the country of Panama. Zoom in progressively upon the Panama Canal and search for the ships traversing this incredible waterway and the massive locks that lift these ships into the upper waterways. What does this suggest about the importance of sending spacecraft to planets to explore their surfaces at close range?
Use Starry Night™ to examine the planet Mars. Select Favourites > Explorations > Mars. Zoom in or out on Mars and use the location scroller to examine the planet’s surface. Based on what you observe, where on the Martian surface would you choose to land a spacecraft to search for the presence of life? Explain the reasons for your choice.
Use the Starry Night™ program to examine Jupiter’s moon Europa. Select Favourites > Explorations > Europa to view this enigmatic moon of our largest planet. Use the location scroller cursor and zoom controls to examine the surface of this moon. Are there any surface features that suggest that this moon might harbor life? Is there any other evidence, perhaps not visible in this simulation, that suggests the possibility that life exists there?
Use Starry Night™ to investigate the likelihood of the existence of life in the universe beyond that found upon Earth. Select Favourites > Explorations > Atlas and then open the Options pane. Expand the Stars layer and the Stars heading and click the checkbox to turn on the Mark stars with extrasolar planets option. Then use the hand tool or cursor keys to look around the sky. Each marked star in this view has at least one planet orbiting around it. Click and hold the Increase current elevation button in the toolbar until the viewpoint is about 1000 ly from Earth. Note that the stars with extrasolar planets are contained in a small knot of stars in the region of our Sun, our solar neighborhood. This is because present techniques place a limit upon the distance to which we can find extrasolar planets in space. There is no logical reason why the same proportion of stars in the rest of the Milky Way, or indeed the rest of the universe, should not have companion planets. Increase current elevation again to about 90,000 ly from Earth to see a view of the Milky Way galaxy. Use the location scroller to view the Milky Way face-on and compare the clump of stars representing the solar neighborhood to the size of the Milky Way Galaxy. Click the Increase current elevation button again until the Viewing Location panel indicates a distance to Earth of about 0.300 Mly (300,000 light-years). In this view, each point of light represents a separate galaxy containing hundreds of billions of stars. Now, gradually increase current elevation to about 1500 Mly (1.5 billion light-years from Earth) to see the entire database of 28,000 galaxies included in the Starry Night™ data bank. The borders of this cube of galaxies reaching out to about 500 Mly from Earth is defined by the limits of the methods for determining distance to galaxies in deep space. In practice, this volume of space represents less than 5% of the size of the observable universe and galaxies abound beyond the limits of this view. To view images of some of these very distant galaxies, open the view named Hubble Deep Field from the Explorations folder in the Favourites pane. This view from the center of Earth is centered upon a seemingly empty patch of sky. Zoom in to see this image of more than 1500 very distant galaxies that were found by the Hubble Space Telescope in a small region of our sky. Then open the view named Hubble Ultra Deep Field and zoom in on an image of over 10,000 galaxies that extends to the limits of our observable universe. (a) Do these views influence your thoughts on the likelihood that life, including intelligent life, exists elsewhere in the universe other than on Earth? Explain your reasoning using the Drake equation as a guide. (b) Why is it unlikely that we will be able to communicate with life forms that might exist on planets in these very distant regions of space?
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Collaborative Exercise
Imagine that astronomers have discovered intelligent life in a nearby star system. Your group is submitting a proposal for who on Earth should speak for the planet and what 50-word message should be conveyed. Prepare a maximum one-page proposal that states (a) who should speak for Earth and why; (b) what this person should say in 50 words; and (c) why this message is the most important compared to other things that could be said. Only serious responses receive full credit.