The universe existed long before the day you were born! In fact, astronomers believe that it is billions of years old. What you may not know is that our understanding of the universe has come about only fairly recently.
Thousands of years ago, ancient sky watchers observed the objects of the night sky. They saw tiny stars, “wandering” stars (which we call planets), and the changing moon.
Four hundred years ago, telescopes were first pointed at the night sky, bringing into view distant stars that were not visible to the unaided eye. Moons were seen orbiting Jupiter, and craters were seen on our own moon. Larger telescopes allowed observers to glimpse fuzzy patches of light; some were large groups of stars, some were remnants of stars’ deaths, and others were “cities of stars” called galaxies.
The largest telescopes on Earth are located on mountaintops, far from city lights and high above many of the Earth’s cloud layers. However, Earthbased telescopes suffer from the haze of the Earth’s atmosphere and are at the mercy of changeable weather patterns. NASA’s Hubble Space Telescope doesn’t have these problems; it orbits the Earth above the clouds and the atmosphere and is able to see celestial objects with incredible clarity. It is with the Hubble Space Telescope that we begin our voyage of discovery, starting at Earth and moving to the edge of our understanding. Prepare to be astonished as you touch the universe!
Note: The Saturn, NGC 4603, and Abell 2218 tactile illustrations must be viewed horizontally. Please turn the book clockwise so that the binding is at the top.