Suppose it turns out that one in 1 million stars has a planet that at some point in its history is home to an advanced civilization. Then the total number of civilizations that have arisen in our galaxy would be closest to
A) 4.
B) 40.
C) 400.
D) 4,000.
F) 40,000.
E) 400,000.
E
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What do astronomers mean by the term "hot Jupiters"?
A) planets with masses and composition similar to what we would expect if Jupiter were hotter B) massive planets that orbit stars that are more massive and hotter than our Sun C) planets with masses similar to Jupiter, but that orbit very close to their central star D) planets with masses similar to Jupiter, but compositions that are similar to Mercury E) planets with masses and orbits similar to Jupiter but for which infrared observations indicate they are surprisingly hot in temperature
In a thick bed of sedimentary rocks we find an igneous dike. The order of formation is
A) together. B) igneous before sedimentary. C) sedimentary before igneous. D) unknown.
Blue light hitting a red sweatshirt is an example of
A) emission. B) reflection or scattering. C) transmission. D) absorption.
If the velocity of an aircraft is doubled, the kinetic energy of the aircraft is also doubled
a. True b. False Indicate whether the statement is true or false