Deck 19: Life in the Universe: Are We Alone

Question 1

The definition of "life" requires only that an entity be able to reproduce itself.

Answer 1

False

Question 2

Organic molecules can only be made by living things.

Answer 2

False

Question 3

Life emerged on Earth within about a billion years after the solar system formed.

Answer 3

True

Question 4

Europa is one of the most promising of the bodies in the outer solar system for life in its salty seas.

Question 5

Astronomical events, such as an asteroid impact or nearly supernova, have probably altered the course of evolution on Earth.

Question 6

Living cells have already been recreated in our laboratories.

Question 7

The Miller- Urey experiment did produce amino acids and proteins.

Question 8

We have found Titan's surface to have perfect living conditions for Earthlike life.

Question 9

The Miller- Urey experiment relied on special conditions found only on Earth.

Question 10

Of the terrestrial planets, Mars seems most promising to exobiologists.

Question 11

The transition from single to multicellular life took over two billion years.

Question 12

The Murchison meteorite, a carbonaceous chondrite, contained many of the amino acids needed by living things on Earth.

Question 13

Interest in life on Mars has died since the latest surveys have found no signs of liquid water on its surface now.

Question 14

From the beginnings of life on Earth, it took less than a billion years for single- celled organisms to evolve to multicellular organisms.

Question 15

Comets were likely a major agent in bringing both water and organic molecules to the surface of the early Earth.

Question 16

The Miller- Urey experiment sought to recreate conditions in Earth's early atmosphere.

Question 17

A Martian meteorite has revealed carbonate rocks and microfossils.

Question 18

Binary star systems are considered good candidates in SETI.

Question 19

NASA has found definite proof for the past existence of life on Mars.

Question 20

The one term of the Drake equation whose value remains completely unknown is the average lifetime of a technological civilization.

Question 21

Most bright blue stars we see with the naked eye are good candidates for life, since they have much larger habitable zones than does the Sun.

Question 22

Due to the first strong commercial radio stations, our radio presence has now extended out to approximately 70 light-years.

Question 23

The Milky Way Galaxy is forming about ten stars per month.

Question 24

Earth- like planets have been observed outside our solar system orbiting in the habitable zone.

Question 25

The water hole is a radio region with lower background noise.

Question 26

Earth behaves as an artificial pulsar, with the strongest pulses for alien observers when North America is either rising or setting.

Question 27

The water hole lies between 18 and 21 cm in wavelength in the radio spectrum.

Question 28

Most radio telescope searches for signs of intelligent life are performed in the water hole.

Question 29

Each factor in the Drake Equation has a well- known, established value.

Question 30

Of the billions of possible combinations of atoms into organic molecules, only about 1500 actually occur.

Question 31

Around Sun- like stars, we have, to date, only found Jupiter- like planets.

Question 32

The Drake Equation seeks to estimate the number of technological civilizations in the galaxy.

Question 33

As yet, no human probe has left our solar system and approached another star.

Question 34

An F- type star would have a larger habitable zone that does our Sun.

Question 35

The Allen Telescope Array is one of the many radio searches for extraterrestrial life.

Question 36

As an artificial radio source, the spinning Earth would have a period of about a day.

Question 37

The radio signals from Earth are greater than those from the Sun.

Question 38

The probes sent out of our solar system were carefully designed to hide any trace of their origin.

Question 39

The water hole is a region around Sun- like stars where liquid water can exist on the surfaces of terrestrial planets.

Question 40

Thanks to the far- flung Voyager and Pioneers, knowledge of our presence has now spread out over 30 light-years.

Question 41

How long ago did multicellular life forms appear in the fossil record?

A) 4.5 billion years ago
B) 3.8 billion years ago
C) one billion years ago
D) 63 million years ago
E) 30 million years ago

Question 42

The Murchison meteorite contained

A) 12 amino acids.
B) bacteria.
C) living cells.
D) RNA.
E) DNA.

Question 43

If we are optimistic in our assumptions about the development of life and intelligence, then the number of technological civilizations currently in the galaxy should equal the

A) average number of planets that produce life.
B) average lifetime of a civilization.
C) average number of planets per star.
D) number of stars in the galaxy's habitable zone.
E) number of stars forming per year.

Question 44

Assuming the conditions ripe for life and intelligence abound in the Galaxy, what factor limits the number of galactic civilizations currently in existence?

A) the number of supernova explosions
B) the average survival time of the civilizations
C) the expansion of the universe
D) the speed of technological development
E) the lack of metals for technology

Question 45

The simplest life forms appeared on Earth by the time it was how old?

A) five million years
B) one billion years
C) 2.5 billion years
D) 3.5 billion years
E) 4.5 billion years

Question 46

Which Jovian moon has gotten the most attention from exobiologists?

A) Ariel
B) Europa
C) Triton
D) Io
E) Miranda

Question 47

How does Drake define a technological civilization?

A) one that can get into space
B) one that can communicate over interstellar distances
C) one that has a written language
D) one that can have the intelligence not to destroy itself
E) one that can construct metal tools

Question 48

Which of the following appears least important in the evolution of life here?

A) the correct distance from the Sun
B) an Earth- like atmosphere
C) the stable luminosity of the Sun for billions of years
D) the magnetic field of the Earth
E) the presence of water and carbon atoms

Question 49

Why do we feel type O and B stars are poor candidates for extraterrestrial life?

A) They do not have a habitable zone.
B) They don't produce enough yellow light.
C) Their lifetime is too short.
D) Their habitable zone lies too close to the star.
E) They don't produce a planetary system.

Question 50

What is meant by the "habitable zone"?

A) the region in dense atmospheres like Jupiter's in which water droplets could form
B) the zone in which terrestrial- sized planets could form around each star
C) the regions near the poles of Mercury in which liquid water might exist
D) the zone in which water can be a liquid around the center of the Galaxy
E) the region around each star in which terrestrial planets could have liquid water on their surfaces

Question 51

Organic molecules are

A) silicon- based.
B) carbon- based.
C) living cells.
D) found only on Earth.
E) not found outside our solar system.

Question 52

According to our definition, we have been a technological civilization for about

A) 10,000 years.
B) 1000 years.
C) 100 years.
D) 10 years.
E) 500 years.

Question 53

Large molecules found in meteorites and interstellar clouds are evidence that

A) life has definitely formed in other places than Earth.
B) chemical evolution has taken place elsewhere in the universe.
C) organic molecules are extremely rare.
D) life originated on Mars before Earth.
E) life is abundant in the galaxy.

Question 54

Which of the following appears most favored by natural selection?

A) live birth
B) intelligence
C) opposable thumbs
D) bipedal locomotion
E) binocular vision

Question 55

The Drake Equation is attempting to find

A) the number of stars that might have planets orbiting them.
B) the number of technological civilizations in the Galaxy at a given moment.
C) the number of planets in the Milky Way Galaxy.
D) the number of planets with life on them in the whole universe.
E) the total number of terrestrial planets ever created.

Question 56

What encouragement for life on Mars came from the Global Surveyor?

A) The ice of the south polar cap is water, not dry ice.
B) spectral evidence for chlorophyll
C) strong photographic evidence for flowing and standing water on Mars in the past
D) The face on Mars is an artificial construct.
E) Hellas has a lake of salt water in its bottom.

Question 57

Which type of molecules, vital to our life, were found to have survived a fiery descent to Earth on meteorites?

A) amino acids
B) lipids
C) vitamins
D) sugars
E) DNA

Question 58

In Drake's equation, which of the following is the closest estimate for the number of stars that are formed in the Milky Way Galaxy?

A) a star a day
B) a star a month
C) a star a year
D) a star a decade
E) a star a century

Question 59

Approximately how long between the evolution of single versus multicellular organisms?

A) 4.5 billion years
B) two billion years
C) one billion years
D) 600 million years
E) 63 million years

Question 60

What important molecules of life did Miller and Urey brew up?

A) RNA
B) antacids
C) lean acids
D) fatty acids
E) amino acids

Question 61

In the habitable zone, surface water must be at least partially

Question 62

The Murchison meteorite in Australia was found to contain .

Question 63

Besides comets and meteorites, we also find organic molecules in the _ deep space.

Question 64

Most SETI searches are done at

A) gamma wavelengths.
B) X- ray wavelengths.
C) visual wavelengths.
D) radio wavelengths.
E) infrared wavelengths.

Question 65

Considering both longevity and luminosity, which of these stars would be the most likely candidate for seeking extraterrestrial intelligence?

A) 61 Cygni, a K2 main- sequence star
B) Barnard's star, a M5 dwarf
C) Spica, a B3 main- sequence star
D) Antares, a M3 supergiant
E) Sirius B, a white dwarf

Question 66

Compared to a G- type star, an F- type will have a(n) habitable zone.

Question 67

The equation was written to assess the probabilities of technological, intelligent life existing in the Galaxy.

Question 68

Our earliest atmosphere, formed by outgassing, was much poorer in than now.

A) carbon dioxide
B) hydrogen
C) methane
D) oxygen
E) nitrogen

Question 69

In a galaxy like ours, the best place for life to form would be in the .

Question 70

In addition to asteroids, impacts also provided the primitive Earth with water and organics.

Question 71

Which of these radio waves would fall in the "water hole"?

A) 150 cm in wavelength
B) 19 cm wavelength
C) 15,000 cm in wavelength
D) 6.563 × 10- 5 cm in wavelength
E) 243 cm in wavelength

Question 72

As a radio source, the period of "pulsar Earth" is

A) 30 minutes.
B) 23 hours, 56 minutes.
C) 24 hours.
D) 29.5 days.
E) 365.25 days.

Question 73

Outside our Earth, the most likely places for life are the planet and jovian moon
.

Question 74

Cultural evolution has primarily taken place over the last years.

A) 10
B) 100
C) 1,000
D) 2,000
E) 10,000

Question 75

Single- celled life ruled the Earth from to billion years ago.

Question 76

Conducted in 1953, the experiments were designed to show what types of complex molecules might have formed in the Earth's primitive environment.

Question 77

In the Miller- Urey experiment, the electric discharge was meant to simulate

A) lightning.
B) radiation.
C) ultraviolet light.
D) meteorite impacts.
E) volcanic heating.

Question 78

If a star system 30 parsecs distant is found to be broadcasting intelligent radio signals, then their news is already approximately years old.

A) 10
B) 30
C) 100
D) 300
E) 1,000

Question 79

An extraterrestrial observer would pick up the strongest radio signals when

A) the Earth was at perihelion.
B) North America was either rising or setting for the observer.
C) at new or full moon.
D) North America was directly in front of the observers.
E) the Super Bowl is on.

Question 80

In addition to the proper chemistry, it is that determines the feasibility of life on a given planet.