Please deactivate your ad blocker in order to see our subscription offer. Cut both of the tubes to that length with a knife or saw. [Related: Best Telescopes for Beginners]. The convex side faces outward. Gluing the spacers in place allow the eyepiece to be adjusted as necessary. Best binoculars 2020: Top picks for skywatching, nature and travel from Celestron, Nikon and other top brands, The best Cyber Monday deals on telescopes, China's Chang'e 5 enters lunar orbit for historic attempt to return moon samples, The best Cyber Monday deals on Orion telescopes and binoculars, Concave-convex lens: Diameter of 49 mm, focal length of 1,350 mm, Plano-concave lens: Diameter of 49 mm, focal length of 152 mm, Outer tube (diameter: 5 cm or 2 inches; length: 2 meters or 7 feet), Inner tube (diameter 4 cm or 1.5 inches; length: 15.25 cm or 6 inches), Concave-convex lens: Diameter 49 mm, focal length 100 mm, Plano-concave lens: Diameter 47 mm, focal length 2000 mm. We used a boxcutter to scrape along the inside of the entry to the pipe to create a smooth area large enough to just slip the objective lens into. The material and tools for this project are: Note: Our photos show flexible piping, which we started out with, but upon completion we preferred a straight pipe. However, it results in a telescope with a magnification of 9x, while our final PVC telescope has a magnification of 20x, much like the telescope Galileo used to discover the four dominant moons of Jupiter. The mailing tubes will be the body of the telescope with the smaller one sliding inside the larger one. An electrician's punch will also serve. Slide the lens and cap into the outer tube. The cardboard tube still fell short of the PVC diameter, so we added cardboard spacers along the side. We slid the eyepiece lens into the tube, working carefully to make sure that it was straight. It is limited by its small field of view, but can inspire an even deeper study of the stars. Place the flat end of the eyepiece lens against the removable cap. As such, we decided to switch the bulk of the body to a PVC pipe. Here is her first-person account of the process. Slide the first spacer in; insert glue through the relevant hole, moving it slightly to spread it around. This article presents two methods of constructing a Galilean telescope — a cardboard tube created by the Galileo Project, which inspired our construction, and a PVC-pipe telescope, which we wound up using for our final project. Add glue through the holes, and turn the lens to spread it around. For example, using a 50-millimeter lens on a telescope with a focal length of 450 mm would get you a power of 9x. Note that the focal length of our lens are 2000/100 = 20, leading to a magnification of 20x. Right: Insert the cardboard eyepiece into the pipe. Cut two pieces from the inner tube, approximately 1 to 1.5 inches (2.5 to 4 centimeters), to create spacers to hold the objective lens. When Italian astronomer Galileo Galilei heard rumors of the first practical telescope at the beginning of the 17th century, he was quick to craft his own version and turn it toward the heavens. Use the drill to make an eyehole in the center of the cap, using light pressure. A Galilean telescope is, in essence, a tube with two lenses placed at either end. The telescope can be focused by sliding the cardboard tube as necessary. It is important to keep the cut as smooth as possible. (Image credit: Galileo Project, Rice University). Slide the inner tube into the outer tube. The telescope can be focused by sliding the cardboard tube as necessary. Magnification is determined by the focal length of the telescope divided by the focal length of the eyepiece. You should keep in mind, too, that a Galilean telescope has a small field of view, which means, for instance, that you won't be able to study the entire face of the moon at once.