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Physics LibreTexts

6.1 Why Study Other Planets?

The study of astronomy in general, and our Solar System in particular, is at its heart an attempt to understand the world around us. Although you may never step foot on Mars, the information we gain from studying other planets can illuminate our own lives and the history of the planet we live on. 

Where did we come from? Why are we here? Where are we going? Are we alone? Human beings have asked these questions throughout history. Some of the answers can be found by studying the origins of the Solar System (where we came from), learning the history of Earth (why we're here), and using that information to speculate about the future of our planet and of life in general (where we're going). Recent discoveries of extra solar planets have expanded our realm of exploration — even if we never find evidence for life elsewhere in this Solar System, we may not be alone in the universe. Our growing understanding of the solar system has allowed us to cast off ancient, limited views of our home, and realize that we live in a much larger cosmic environment.

The poet T.S. Eliot said, "We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time." Other planets can teach us about our own — they can be compared and contrasted to the Earth at different times in its evolution, or as pictures of "what might have been" had circumstances been different. Studies like this have informed diverse subjects, from the extinction of the dinosaurs to the formation of the Earth's Moon. We have also learned much about environmental issues such as global warming and the ozone layer from our neighboring planets.

What lies ahead in space exploration? Visionaries argue that our future is in space. In space, we will continue the exploration that first showed us the shape and size of our own planet. Someday we will live and work in space. These visionaries foresee more astronomical telescopes in orbit above our cloudy atmosphere. They foresee space-borne technology protecting the planet from large asteroid impacts that have the potential of destroying all life on Earth. They foresee the development of giant solar collectors sending free, abundant solar energy down to the surface.

Artist's concept of asteroid mining. Click here for original source URL.

In addition to idealistic visions of a science-fiction future, there are many pragmatic and economic reasons to stay active in space. The ability to launch satellites cheaply will transform global communications. It may someday become economically feasible to mine rare metals from asteroids. Over the past few decades, the space program has transformed from a vehicle for military technology into a means for governments to conduct high-level scientific research. In the future, the commercialization and popularization of space will lead to many new possibilities. 

Amatur astronomers watching a meteor shower. Astronomy can inspire people of any age. Click here for original source URL.

One of the most powerful motives for continuing our explorations is the universal fascination people have with space. Millions of people look with wonder at images of other worlds sent back by interplanetary probes and landers. Every space mission is a newsworthy event, accompanied by widely viewed press releases and extensive educational components. Children excited by studying Mars in school may be inspired to pursue careers in science or engineering. People of all ages are captivated by the mystery and promise of space. The benefits to humanity of space exploration are not merely practical, but emotional and inspirational.