9/25/2020Ch. 1 Introduction - Astronomy | OpenStax1/3Chapter Outline1.1The Nature of Astronomy1.2The Nature of Science1.3The Laws of Nature1.4Numbers in Astronomy1.5Consequences of Light Travel Time1.6A Tour of the Universe1.7The Universe on the Large Scale1.8The Universe of the Very Small1.9A Conclusion and a BeginningFigure 1.1Distant Galaxies.These two interacting islands of stars (galaxies) are so far away that their light takes hundreds ofmillions of years to reach us on Earth (photographed with the Hubble Space Telescope). (credit: modification of work byNASA, ESA, the Hubble Heritage (STScl/AURA)-ESA/Hubble Collaboration, and K. Noll (STScl))We invite you to come along on a series of voyages to explore the universe as astronomers understand ittoday. Beyond Earth are vast and magnificent realms full of objects that have no counterpart on our homeplanet. Nevertheless, we hope to show you that the evolution of the universe has been directly responsiblefor your presence on Earth today.Along your journey, you will encounter:a canyon system so large that, on Earth, it would stretch from Los Angeles to Washington, DC (Figure1.2).
9/25/2020Ch. 1 Introduction - Astronomy | OpenStaxFigure 1.2Mars Mosaic.This image of Mars is centered on the Valles Marineris (Mariner Valley) complex of canyons, which isas long as the United States is wide. (credit: modification of work by NASA)
Get answer to your question and much more
9/25/2020Ch. 1 Introduction - Astronomy | OpenStax3/3Figure 1.3Stellar Corpse.We observe the remains of a star that was seen to explode inour skies in 1054 (and was, briefly, bright enough to be visible during the daytime). Today,the remnant is called the Crab Nebula and its central region is seen here. Such explodingstars are crucial to the development of life in the universe. (credit: NASA, ESA, J. Hester(Arizona State University))Such discoveries are what make astronomy such an exciting field for scientists and many others—but youwill explore much more than just the objects in our universe and the latest discoveries about them. We willpay equal attention to theprocessby which we have come to understand the realms beyond Earth and the