The Planets PDF Free Download
The amazing diversity of worlds in our solar system has inspired people for generations. Our immediate neighborhood in space includes a star powered by nuclear fusion, large worlds of swirling gases, smaller planets made of rock and metal, and countless tiny bodies. In the farther reaches of the solar system, four large gas planets orbit the Sun: Jupiter, Saturn, Uranus, and Neptune. Four smaller terrestrial planets orbit closer to home: Earth, Venus, Mars, and Mercury. Also nearby is the main belt of asteroids. Other tiny, ice-covered bodies, mostly found in the realms beyond the planets, orbit in a few distinct groups at the edge of the Sun’s gravitational influence. Although it is small compared to the Sun and the gas planets, the most important place to us is, of course, Earth. It is the only world so far found to support life, and in our exploratory missions across the solar system we have yet to find anywhere quite like home. People have stood on only one other world besides Earth.
Astronauts reached the surface of the Moon in the 1960s in one of the greatest stories of human enterprise. We have also sent spacecraft to other planets, acquiring a vast amount of data. Our robotic machines crawl over the surface of Mars and return images of a dusty, dry world, but one that reminds us of the desert landscapes on Earth. Venus, cloaked in thick, hot clouds, seems a very alien place in comparison. Other intriguing places that continue to fascinate us include Europa and Enceladus, ice-covered moons of outer planets that both contain layers of liquid water under the surface. The exotic beauty of our solar system has captured the imagination of people everywhere. This book shows in detail what each world has in common, what sets each apart from the others, and how they all fit together within our small region of the universe. I hope that The Planets fulfills part of your dreams of discovery.