Life in the Universe PTQ´S

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

For the complex biochemical reactions of life (as we know it) to happen, a solvent is required. What is that solvent for life on Earth? a. ammonia b. methane c. water d. carbon dioxide e. diet Coke or diet Pepsi

c. water

Scientists are impressed with extremophiles, life forms that can survive under what seems to humans to be extremely unpleasant conditions. In which of the following environments have we not found life: a. temperatures near or below the freezing point of water b. temperatures near or above the boiling point of water c. very acid environments d. conditions where the radiation dosage is high e. conditions resembling the photosphere of the Sun

e. conditions resembling the photosphere of the Sun

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

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

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

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

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

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

a. oxygen

Which of the following is a recent (last few decades) discovery that confirms the key idea of the Copernican Principle? a. that the Earth has a Moon b. that gravity waves exist c. that planets around other stars are common d. that 65 million years ago a large asteroid hit the Earth c. that planets around other stars are common

c. that planets around other stars are common

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

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

b. a planet about 1.05 AU from a G-type main sequence star

Photosynthesis releases a particular gas as a byproduct. This gas is: a. carbon dioxide b. oxygen c. water vapor d. methane e. DNA

b. oxygen

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

d. the fact that most of our atmosphere is made of nitrogen

When they talk about the Copernican principle, philosophers and astronomers mean that: a. the idea that Copernicus was the greatest astronomer who ever lived and the model for astronomers ever since b. the idea that everything in the universe revolves around the Sun c. the idea that everything in the universe rotates and revolves (i.e. has angular momentum) d. the idea that there is nothing special about our place in the universe e. the idea that the universe is expanding in every direction that we look

d. the idea that there is nothing special about our place in the universe

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

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

e. on the surface of some of the smaller members of the Kuiper Belt

If you wanted to find a type of atom in your little finger that has been in its present form (been the same element) since the beginning of the universe, which element should you look for? a. hydrogen b. carbon c. irond. oxygen e. Einsteinium

a. hydrogen

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

In which of the following places have astronomers NOT found evidence for the building blocks of life (organic compounds)? a. Earth b. comets c. meteorites d. clouds of interstellar gas and dust e. we have found evidence for such materials in all of the above sites

e. we have found evidence for such materials in all of the above sites

Photosynthesis was a great step forward in the evolution of life on Earth, because with photosynthesis a. we have the way in which life on Earth and life on Mars resemble each other b. life could, for the first time, reproduce (make copies of itself) c. we have the common ancestor that gave rise to every species of life now on Earth d. life could extract chemical energy from sunlight e. life did not have to evolve any further

b. life could, for the first time, reproduce (make copies of itself)

One place that astronomers think might have had life start long ago is Mars. Which of the following is not a discovery that we have made on Mars so far? a. observing what looks like dried up river channels from orbiting spacecraft b. the discovery of organic materials (the chemical building blocks of life, such as amino acids) by spacecraft that have landed c. the discovery that Mars long ago had plenty of flowing water, from the composition and layering of some of the rocks examined by Mars rovers d. the discovery of mudstone on Mars, which indicates that ancient Mars may have been more habitable than Mars today e. the discovery of significant amounts of frozen water on Mars, under the surface

b. the discovery of organic materials (the chemical building blocks of life, such as amino acids) by spacecraft that have landed

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

What makes the Earth different from the other worlds that might have life in the solar system (and easier to detect from far away) is that only Earth a. has liquid water on it; no other world in our solar system has water b. has temperatures in some places where chemical change is possible c. has a solid surface d. has a biosphere on its surface where photosynthesis can take place e. has the chemical ingredients from which life might begin

d. has a biosphere on its surface where photosynthesis can take place

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

d. much more narrow (small) than the diameter of any planet

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

e. There are plumes of salty vapor coming from cracks in Enceladus' surface

What does the Fermi Paradox say? a. Given all the time since the Big Bang and all the stars, why has some form of intelligent life in the Galaxy not established a network throughout the Galaxy and visited us? b. Given the size of the Galaxy, there should be an exact duplicate of the Earth somewhere and we should have found it c. If life on Earth took a miracle to form, then there should be no life anywhere else d. If all the planets in our solar system besides Earth are lifeless, then it must follow that most of the planets around other stars are also lifeless and finding life is hopeless e. When Fermi got ill, he always needed two doctors to diagnose him

a. Given all the time since the Big Bang and all the stars, why has some form of intelligent life in the Galaxy not established a network throughout the Galaxy and visited us?

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

Chemically, the process leading to life on Earth began with lots of liquid water and a. helium b. hydrocarbons (molecules which had hydrogen and carbon) c. radium and its isotopes d. molecules containing iron e. molecules containing iridium

b. hydrocarbons (molecules which had hydrogen and carbon)

In the early 1950's, Stanley Miller and Harold Urey conducted a series of pioneering laboratory experiments involving simulations of the early Earth. What did these experiments reveal? a. that the early Earth was constantly bombarded by asteroids and comets b. that under the conditions on the early Earth, they could synthesize some of the building blocks of life in a laboratory c. that the early Earth was much hotter than anyone had suspected d. that the early Earth had received microscopic life in meteorites that had come from Mars in the very beginning of the solar system's history e. that the early Earth had to have been covered with a thick layer of ice, just like Jupiter's satellite Europa

b. that under the conditions on the early Earth, they could synthesize some of the building blocks of life in a laboratory

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

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

Scientists think that the life we have on Earth today originated some time between 3.5 and 3.8 billion years ago. Yet the solar system and the Earth are known to be at least 4.5 billion years old. Which of the following is one reason life as we know it had to wait until 3.5 to 3.8 billion years ago to get going? a. supernovae were exploding near the Sun's location every year back then b. the Sun was so much cooler when the Earth formed, that the Earth's oceans (and even Mars' oceans) were frozen over for billions of years c. before 3.8 billion years ago, the Earth was experiencing a period of heavy bombardment, when giant chunks of rock and ice left over from planet formation kept hitting our planet and making it uninhabitable d. experiments like the one done by Miller and Urey show that life on Earth could not form until plants produced a lot of oxygen for our atmosphere e. the early solar system was filled with dark matter, and life could not form with so much dark matter around

c. before 3.8 billion years ago, the Earth was experiencing a period of heavy bombardment, when giant chunks of rock and ice left over from planet formation kept hitting our planet and making it uninhabitable

Think for a moment about an atom of the element lead (atomic number 82) inside the radio that you listen to in the morning. In which of the following places has this atom probably NOT been during the course of its existence? a. a previous generation star b. a supernova explosion c. the Sun d. a cloud of gas and dust which would clump to become a star and a family of planets e. the Earth's crust

c. the Sun

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

From a scientific perspective, which of the following statements about life elsewhere in the universe is best supported by current evidence? a. we have good evidence that life exists on many planets around other stars b. we only have evidence that life exists around three other stars c. the government has evidence (which it is not releasing) that there is at least one other intelligent life form on a planet orbiting another star d. while we have evidence of the building blocks of life elsewhere in the universe, we have no definite evidence about life around other stars at this time e. there is no evidence for intelligent life anywhere, even on Earth

d. while we have evidence of the building blocks of life elsewhere in the universe, we have no definite evidence about life around other stars at this time

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