30.4.0 The Search for Extraterrestrial Intelligence

27. Which band of the electromagnetic spectrum do astronomers suggest is likely to be the best (cheap, little competition from nature, penetrates atmospheres) for communication between civilizations around different stars? a. radio waves b. x-rays c. ultra-violet d. infrared e. gamma rays

a. radio waves

34. We receive a radio message from a civilization around a star about 40 lightyears from Earth? If we reply right away, how long will it be between the time THEY sent the message and the time they receive our reply? a. 40 years b. 80 years c. 400 years d. 20 years e. it depends on the speed of the radio wave; so it can't be calculated from the information given

b. 80 years

29. The first search for radio messages from extra-terrestrial civilizations was called a. Project Phoenix b. Project Ozma c. Project Serendip d. Project META e. Project ASTRO

b. Project Ozma

32. What recent series of discoveries has made astronomers more optimistic about our prospects of finding life out there? a. the discovery of a form of silicon-based life in the volcanic vents of Venus b. the discovery of planets around thousands of stars in our Galaxy c. the discovery of a black hole approaching our solar system at rapid speed d. the discovery of many key building blocks of life in a crater near the polar region of the Moon e. the discovery of a spaceship, built by an alien civilization, that crashed in New Mexico

b. the discovery of planets around thousands of stars in our Galaxy

30. The fastest speed at which we might communicate with another technological civilization among the stars (according to our present understanding of science) is a. the speed of sound (the natural speed for messages) b. the speed of light c. the speed of the Voyager spacecraft (which is typical of our space probes) d. instantly (as fast as we want) -- if we only knew where they were located e. the orbital speed of the Earth

b. the speed of light

25. Which of the following spacecraft is NOT leaving the solar system? a. Voyager 1 b. Voyager 2 c. Galileo d. Pioneer 10 e. Pioneer 11

c. Galileo

26. If alien beings found one of the Voyager spacecraft in a million years, what would they find aboard? a. a container with a concentrated sample of the most common Earth bacteria b. a flag from the Soviet Union c. an audio and video record d. a human skull done in bronze e. a video tape with every episode of the original "Star Trek" TV series

c. an audio and video record

31. The Drake Equation allows astronomers to estimate a. the age of the universe b. the location of the Sun within the Milky Way Galaxy c. the number of civilizations out among the stars with which we might communicate d. the rate at which the universe expands e. the number of ducks that we in the United States use for food each year

c. the number of civilizations out among the stars with which we might communicate

36. In a globular cluster, astronomers (someday) discover a star with the same mass as our Sun, but consisting entirely of hydrogen and helium. Is this star a good place to point our SETI antennas and search for radio signals from an advanced civilization? a. yes, because such a star is probably old and a technological civilization will have had a long time to evolve and develop there b. yes, because we have already found radio signals from another civilization living near a star in a globular cluster c. no, because such a star would most likely not have a stable (main-sequence) stage that is long enough for a technological civilization to develop d. no, because such a star (and any planets around it) would not have the heavier elements (carbon, nitrogen, oxygen, etc.) that we believe are necessary to start life as we know it e. yes, because globular clusters are among the closest star clusters to us, so that they would be easy to search for radio signals

d. no, because such a star (and any planets around it) would not have the heavier elements (carbon, nitrogen, oxygen, etc.) that we believe are necessary to start life as we know it

35. Which of the following events in cosmic history is the most recent? a. the birth of the universe b. the formation of our Galaxy c. the formation of the Sun d. the formation of life on Earth e. you can't fool me, all of the above happened at roughly the same time

d. the formation of life on Earth

28. Which of the following questions is NOT part of what astronomers call the "cosmic haystack problem" in receiving messages from other civilizations in space? a. we don't know what star might have planets with intelligent life b. we don't know what channel they may be using to send messages c. we don't know whether the signal is always on (continuous) or only for a brief time every cycle d. we don't know how to receive signals in the wavelength range that is the most likely for interstellar communications e. we don't know how other civilizations might encode messages in the carrier wave they send

d. we don't know how to receive signals in the wavelength range that is the most likely for interstellar communications

33. What new technology has made it possible for astronomers to do "optical SETI" - searching for signals for extra-terrestrial civilization, not in the radio band of the spectrum, but in the visible-light band? a. the Hubble Space Telescope was put into orbit b. radio and TV signals have gone silent as much of the US adopts cable c. astronomers have developed adaptive optics to deal with the twinkling of the stars d. astronomers have built radio telescopes that can pick up the 3-degree microwave background e. we have developed the ability to make laser pulses that are briefly brighter than the Sun

e. we have developed the ability to make laser pulses that are briefly brighter than the Sun

24. Which of the following is a good summary of what most astronomers think about UFO reports in the popular media? a. so far there is no scientific evidence that UFO's have anything to do with life outside the Earth b. it is now clearly established that alien spacecraft have crashed on Earth; we have the bodies of the aliens who flew them here c. while no UFO's have landed, we have overheard communications between them with our radio surveys and thus have evidence that there are intelligent creatures aboard them d. UFO's are now known to come from the planet Mars, the only other planet that we know has life on it e. UFO's have kidnapped a number of Earth inhabitants, including at least one well-known astronomer; her reports convinced other scientists that UFO's are indeed alien spaceships

a. so far there is no scientific evidence that UFO's have anything to do with life outside the Earth