[Solved] What Makes the Earth Different from the Other Worlds That

According to astronomers, which of the following places in the outer parts of our solar system might be a reasonable place for life to exist? A) in the core of the planet Saturn B) in the rings of Neptune C) in the mountains of Pluto D) under the ice of Jupiter's moon Europa E) on the surface of some of the smaller members of the Kuiper Belt

What discovery about Saturn's moon Enceladus has encouraged astronomers to think of that moon as a possible place where life might exist? A) Enceladus has a strong magnetic field B) Enceladus has rivers of liquid water flowing on its surface C) There are radio signals coming from Enceladus which indicate they might be made by intelligent life D) Enceladus has a thick atmosphere with a significant amount of oxygen E) There are plumes of salty vapor coming from cracks in Enceladus' surface

One reason that some scientists think that there may be life under the ice-crust of Jupiter's moon Europa is that: A) Europa is unusually warm on its surface; in some places the climate resembles Hawaii on Earth. B) Life has already been found on Io, Jupiter's inner-most large moon C) Life has been found on Earth, at the bottom of the ocean, deriving its energy not from sun-light but from hot mineral-laden vents coming from deeper inside our planet; something similar could happen at the bottom of the ocean on Europa D) meteorites blasted off Europa have been found on Earth and we detect the building blocks of life inside these meteorites from Europa E) we are receiving intriguing radio messages from Europa that indicate some form of intelligence lives there

Which of the following is, to the best of our knowledge, in the habitable zone of its star: A) a "hot Jupiter" taking 4 days to orbit a G-type main sequence star B) a planet about 1.05 AU from a G-type main sequence star C) a Jupiter-mass planet taking 15 years to orbit a K-type main sequence star D) a planet in an orbit the size of the Earth's around a red giant star E) all of the above

Astronomers have discovered a planet orbiting Proxima Centauri, the star closest to the Sun. This is a star of spectral type M, with 12% the mass of the Sun and 15% the size of the Sun. The habitable zone around this star would be A) much larger (wider) than the Sun's B) much closer to the star than the Sun's C) in about the same place as the Sun's asteroid belt D) much more narrow (small) than the diameter of any planet E) the source of all the UFO's that have been reported by UFO believers on Earth

Photosynthesis, once it was planet-wide, changed the atmosphere of the Earth by introducing a significant amount of A) oxygen B) carbon dioxide C) methane D) ammonia E) vibranium

Which of the following is a biomarker that could be used from an observatory around a nearby star, with the right equipment, to identify the Earth as a planet with life: A) the presence of a large moon around the Earth B) free oxygen in the Earth's atmosphere C) the abundance of micro-organisms in the deserts of the Earth D) the fact that most of our atmosphere is made of nitrogen E) ice in the Earth's polar caps Section 30.4: The Search for Extraterrestrial Intelligence

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

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

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