Discovering the Universe

Gravity: It's Universal We owe our lives to gravity. It holds the atmosphere to Earth and keeps us all from falling off into space. Not to mention that without... Space Games Here on Earth, we tend to take gravity for granted. Yet the astronauts aboard the Space Station need to learn how to do everything... Space Shuttle Orbiter Did you know that satellites and the Space Shuttle don't need engines to power their orbits? See how Earth's gravitational pull bends... Filtering Light All the color photos of astronomical phenomena that we see in magazines and books begin as three separate images—one red, one... Gathering Light While refracting and reflecting telescopes use different means of collecting light, the same principle applies to both—the... Building a Simple Refracting Telescope What could Galileo see when he looked through his telescope? Build a refracting telescope with lenses similar to the ones he used,... Focal Point What is a telescope's focal point, and why is knowing its location so important to astronomers? Grab a flashlight, an empty soda... Digital Images: The Universe Exposed For most of human history, recording a star meant describing it with words or drawing a picture. The 19th-century invention of photography... Pixel This! No doubt you've received—or even sent—a digital image. But do you know how these pixel-based photographs work? You will... 3-D Model of the Big Dipper In outer space, you might not recognize the Big Dipper. The stars that form this constellation exist in 3-D not 2-D—so the... The 3-D Universe A 2-D map is a great guide here on Earth—and virtually worthless for finding your way around in outer space. Take a 3-D look... Parallax When it comes to observing stars, our eyes have their limitations. Take a look at how astronomers combat these limits and accurately... Astronomy Books for Adults Focus on the best books about astronomy, astrophysics, light, telescopes, digital imaging, and the 3-D universe with this list of... Telescopes: Super Views from Space It probably comes as no surprise that telescopes do a better job of collecting light and observing outer space than your eyes. But... Light: Its Secrets Revealed Did you know that when you look at a star, your eyes are capturing light that traveled all the way from the star to your eye? Learn... Detecting UV Light You can't see the Sun's ultraviolet rays with your eyes—you just see their results on your freckled, tanned, or sunburned skin.... White Light and Colored Light When does mixing every color under the rainbow create pure white rather than a murky brown or black? When light, not paint, is the... Building a Spectroscope White light is a mixture of all colors of visible light, but it doesn't always include every color of the rainbow. Build a spectroscope,... Calculate Planetary Distances Students use Google Earth and an online calculator to create a scale model of the distances among the objects in the Solar System.