Concept explainers
What evidence can you give that we live in a galaxy?
The evidence that life exists in a galaxy.
Answer to Problem 1RQ
The living organisms of the Milky Way galaxy are made up of the same constituents as the living organisms on earth are made up of. Hence, the life exists in a Milky Way galaxy.
Explanation of Solution
The galaxy in which life exists is the Milky Way Galaxy, the diameter of this galaxy is more than
The Milky Way Galaxy in which the life exists and which the living organisms live in has millions of stars, these stars are made up of the same basic constituents that the living organisms of the Earth and most of the atoms are made up of.
Therefore, the life exists in Milky Way galaxy.
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Chapter 15 Solutions
Foundations of Astronomy (MindTap Course List)
- Assume that the average galaxy contains 1011MSunand that the average distance between galaxies is 10 million light-years. Calculate the average density of matter (mass per unit volume) in galaxies. What fraction is this of the critical density we calculated in the chapter?arrow_forwardWhy didnt astronomers before Shapley realize how large our Galaxy is?arrow_forwardWhere might the gas and dust (if any) in an elliptical galaxy come from?arrow_forward
- What will be the long-term future of our Galaxy?arrow_forwardIf we now realize dwarf ellipticals are the most common type of galaxy, why did they escape our notice for so long?arrow_forwardSuppose the average mass of a star in the Galaxy is one-third of a solar mass. Use the value for the mass of the Galaxy that we calculated in Exercise 25.19, and estimate how many stars are in the Milky Way. Give some reasons it is reasonable to assume that the mass of an average star is less than the mass of the Sun.arrow_forward
- How are distant (young) galaxies different from the galaxies that we see in the universe today?arrow_forwardIf the diameter of the Milky Way Galaxys visible disk, 80,000 ly, is represented in a model by a dinner plate with a diameter of 10 inches, what is the model distance to galaxy M31, 2.6 millionly away? What is the model distance to the Virgo galaxy cluster, 16 Mpc away? (Convert answers to feet.)arrow_forwardBriefly describe the main parts of our Galaxy.arrow_forward
- What is the evidence that star formation began when the universe was only a few hundred million years old?arrow_forwardSuppose the Sagittarius dwarf galaxy merges completely with the Milky Way and adds 150,000 stars to it. Estimate the percentage change in the mass of the Milky Way. Will this be enough mass to affect the orbit of the Sun around the galactic center? Assume that all of the Sagittarius galaxy’s stars end up in the nuclear bulge of the Milky Way Galaxy and explain your answer.arrow_forwardAccording to Hubble’s law, what is the recessional velocity of a galaxy that is 108 light-years away from us? (Assume a Hubble constant of 22 km/s per million light-years.)arrow_forward
- 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