Life in the Universe (4th Edition)
4th Edition
ISBN: 9780134089089
Author: Jeffrey O. Bennett, Seth Shostak
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 9, Problem 36POS
Cost-Effective Exploration. Given its budget, NASA can’t afford to launch many spacecraft pet year. Yet the public is interested to know if there’s life in space. If you were named the NASA Administrator and had money for only one mission to the outer solar system to hunt for biology, which world would you choose to investigate? Defend your position.
Expert Solution & Answer
Want to see the full answer?
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…
Tutorial
A radio broadcast left Earth in 1925. 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 0.30 and that, in a given planetary
system, the average number of planets that have orbited in the habitable zone for 4 billion years is 0.85. 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 1925, distance in light years = time since broadcast left Earth.
d = tnow - tbroadcast
d =
light years
Submit
Skip (you cannot come back)
The principle cause of our intense interest in Mars in the decades before the dawn of the space age was that
Answers:
A.
a few astronomers believed that they saw evidence of an intelligent civilization on Mars.
B.
Mars has seasons just like the Earth and therefore should be inhabitable by humans.
C.
Mars has an unusual surface color and global dust storms, creating strange weather patterns.
D.
Mars has unusual orbital properties making our understanding of its motion around the Sun very difficult.
Chapter 9 Solutions
Life in the Universe (4th Edition)
Ch. 9 - Briefly explain how the larger jovian moons tend...Ch. 9 - Briefly describe the cause of the tides on Earth,...Ch. 9 - What is synchronous rotation, and why is it so...Ch. 9 - What is tidal heating? Briefly explain how it can...Ch. 9 - Describe the evidence suggesting that Europa has a...Ch. 9 - What energy sources might be available to life on...Ch. 9 - Describe the evidence for subsurface oceans on...Ch. 9 - Why was Titan chosen for such intense study by the...Ch. 9 - Based on recent data, describe the general nature...Ch. 9 - What evidence suggests that Enceladus might be...
Ch. 9 - Could Triton be habitable? Briefly discuss the...Ch. 9 - What do we mean by chemical equilibrium and...Ch. 9 - Prob. 13RQCh. 9 - Based on our understanding of the chemistry of...Ch. 9 - Io is riddled with volcanoes because of its...Ch. 9 - Europa is likely to have fishlike organisms the...Ch. 9 - While Europa, Ganymede, and Callisto are all...Ch. 9 - The fact that our Moon keeps one side always...Ch. 9 - Titan is simply too cold to have any life.Ch. 9 - Triton might have life that uses liquid ammonia,...Ch. 9 - Io doesnt have a significant atmosphere because it...Ch. 9 - Orbital resonances like those among Io, Europa,...Ch. 9 - If there is life on Enceladus, it probably gets...Ch. 9 - If our solar system is typical, other star systems...Ch. 9 - The moons of Saturn may have large amounts of...Ch. 9 - Which statement about synchronous rotation is...Ch. 9 - Io is covered in volcanoes while Europa is covered...Ch. 9 - Which of the following is not an indication of...Ch. 9 - Photosynthesis is an unlikely source of energy for...Ch. 9 - Its assumed that, even if Europa has life, the...Ch. 9 - The chances for life on Titans surface are...Ch. 9 - Where might we find liquid water on Titan? (a) in...Ch. 9 - Why were scientists so surprised to find active...Ch. 9 - Chemical disequilibrium is likely to be present in...Ch. 9 - Cost-Effective Exploration. Given its budget, NASA...Ch. 9 - Lessons for Life. Considering everything weve...Ch. 9 - Exploring Europa I. Although Europa is a promising...Ch. 9 - Exploring Europa II. One suggestion for...Ch. 9 - Europan Fish. On Earth, fish breathe oxygen that...Ch. 9 - Life on Titan. Several possibilities have been...Ch. 9 - Migrating Life. As we discussed in Chapter 6,...Ch. 9 - Orbital Resonances I. Using the data in Appendix...Ch. 9 - Orbital Resonances II. Using the data in Appendix...Ch. 9 - Tidal Force on the Moon. In Cosmic Calculations...Ch. 9 - Tidal Force on Io. Using the procedure from Cosmic...Ch. 9 - Tidal Force on Europa and Ganymede. Using the...Ch. 9 - Limited Thinking. Throughout this book, we have...Ch. 9 - Europa Orbiter. Find out the current status of...
Additional Science Textbook Solutions
Find more solutions based on key concepts
3. What is free-fall, and why does it make you weightless? Briefly describe why astronauts are weightless in th...
The Cosmic Perspective
34.2 The image of a tree just covers the length of a plane mirror 4.00 cm tall when the mirror is held 35.0 cm ...
University Physics with Modern Physics (14th Edition)
Using the definitions in Eqs. 1.1 and 1.4, and appropriate diagrams, show that the dot product and cross produc...
Introduction to Electrodynamics
An electric field and a magnetic field have the same energy density. Find an expression for the ratio E/B and e...
Essential University Physics: Volume 2 (3rd Edition)
18. High-energy cancer treatment. Scientists are working on a new technique to kill cancer cells by zapping the...
College Physics (10th Edition)
The electric Field at the center of a uniformly charged ring is obviously zero, yet Example 22.6 shows that the...
Essential University Physics (3rd Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- If we do find life on Mars, what might be some ways to check whether it formed separately from Earth life, or whether exchanges of material between the two planets meant that the two forms of life have a common origin?arrow_forwardMars and Europa are two Solar System bodies that are considered possible habitats for Earth-like life. Why?arrow_forwardWhat evidence do scientists have that life on Earth began in the sea?arrow_forward
- Molecules of which gas were needed in Earths atmosphere for life to evolve from living in the sea to living on the land? Why?arrow_forwardWhy is life unlikely to be found on the surface of Mars today?arrow_forwardWhat are the advantages to using radio waves for communication between civilizations that live around different stars? List as many as you can.arrow_forward
- Why are we limited to finding life on planets orbiting other stars to situations where the biosphere has created planet-scale changes?arrow_forwardWhat is a habitable zone?arrow_forwardIf you represent Earths history by a line that is 1 m long, how long a segment would represent the 400 million years since life first moved onto the land? How long a segment would represent the 4-millionyear history of humanoid life?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage LearningStars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage LearningAstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
- Stars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
General Relativity: The Curvature of Spacetime; Author: Professor Dave Explains;https://www.youtube.com/watch?v=R7V3koyL7Mc;License: Standard YouTube License, CC-BY