Life in the Universe (4th Edition)
4th Edition
ISBN: 9780134089089
Author: Jeffrey O. Bennett, Seth Shostak
Publisher: PEARSON
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Textbook Question
Chapter 1, Problem 10RQ
What do we mean by astrobiology? What are the major areas of research in astrobiology?
Expert Solution & Answer
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Check out a sample textbook solutionStudents have asked these similar questions
Tutorial
A radio broadcast left Earth in 1923. How far in light
years has it traveled?
If there is, on average, 1 star system per 400 cubic light
years, how many star systems has this broadcast
reached?
Assume that the fraction of these star systems that
have planets is 0.50 and that, in a given planetary
system, the average number of planets that have
orbited in the habitable zone for 4 billion years is 0.40.
How many possible planets with life could have heard
this signal?
Part 1 of 3
To figure out how many light years a signal has
traveled we need to know how long since the signal left
Earth. If the signal left in 1923, distance in light years =
time since broadcast left Earth.
d = tnow - broadcast
d = 97
97 light years
Part 2 of 3
Since the radio signal travels in all directions, it
expanded as a sphere with a radius equal to the
distance it has traveled so far. To determine the
number of star systems this signal has reached, we
need to determine the volume of that sphere.
V, =
Vb…
Which of the following is least reasonable regarding the difficulty in contacting extraterrestrial life using space flight and radio communication.
Group of answer choices
Space flight to the nearest star would take thousands of years with current technology.
Even if another intelligent civilization is within a few hundred light-years of us, conversations would be very slow with a turnaround time of decades or even centuries.
The spacecraft that NASA sent to Proxima Centauri a few years ago should be approaching its target within a decade or two, depending on solar wind conditions.
Earth has been broadcasting at radio wavelengths since the 1930's, so any civilization within a radius of about 100 light-years or so could have received the broadcast by now.
Without some major breakthrough, interstellar space flight is totally impractical.
Which of the following seems least reasonable regarding life on Earth?
Group of answer choices
There is much scientific evidence suggesting that all creatures living on Earth today appear to have evolved from a common ancestor.
Louis Pasteur discredited the concept of spontaneous generation by demonstrating that even bacteria and other microorganisms arise from parents resembling themselves.
There is ample physical evidence that the earliest life forms on Earth were multicellular creatures, perhaps resembling some of our primitive fish.
When the earth formed some 4.6 billion years ago, it was a lifeless, inhospitable place.
Before the mid-17th century, most people believed that God had created humankind and other higher organisms and that insects, frogs, and other small creatures could arise spontaneously in mud or decaying matter
About billion years into its development, the Earth it was teeming with organisms resembling blue-green algae.
Chapter 1 Solutions
Life in the Universe (4th Edition)
Ch. 1 - Why are scientists interested in the possibility...Ch. 1 - People have long been interested in life beyond...Ch. 1 - Prob. 3RQCh. 1 - Prob. 4RQCh. 1 - What do we mean by a habitable world? Does a...Ch. 1 - What do we mean by the universality of physics and...Ch. 1 - Besides Earth, what worlds in our solar system...Ch. 1 - Prob. 8RQCh. 1 - Prob. 9RQCh. 1 - What do we mean by astrobiology? What are the...
Ch. 1 - An extrasolar planet is (a) a planet that is...Ch. 1 - A habitable planet is (a) a planet that has oceans...Ch. 1 - Prob. 13TYUCh. 1 - Prob. 14TYUCh. 1 - The correct order for the eight official planets...Ch. 1 - Today, the research known as SETI is conducted...Ch. 1 - Prob. 17TYUCh. 1 - Scientists today are interested in searching for...Ch. 1 - Based on current evidence, the object in our solar...Ch. 1 - Prob. 20TYUCh. 1 - Universal Laws. Briefly discuss how the idea that...Ch. 1 - The Science of Astrobiology. The study of...Ch. 1 - Conducting the Search. Given the large number of...Ch. 1 - Funding for Astrobiology. Imagine that you are a...
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