Introduction: The Urban Stargazer's Tube: Build Your Own Dark Sky Viewfinder
In our brilliantly lit cities, the glow of light pollution washes out all but the brightest stars, making casual stargazing nearly impossible. This project offers a simple, low-cost solution: the Urban Stargazer's Tube. By creating an isolated, dark viewing chamber that shields your eyes from direct, peripheral light pollution, allowing them to fully adapt to the dark and reveal faint celestial objects normally invisible in the urban sky.
Supplies
Cardboard
The primary material for the tube structure.
Black Paint (Acrylic)
To create a light-absorbing interior and exterior.
Glue Gun & Glue Sticks
For fast and secure assembly of the tube sections.
Utility Knife
For accurately cutting the cardboard pieces.
Ruler
To ensure straight cuts and for scoring the fold lines.
Cutting Mat
To protect your work surface and provide a measured grid.
Pen/Pencil
For marking measurements.
Eraser (Optional)
To clean up pencil marks.
Paint Brush
To apply the black paint.
Step 1: Mark and Measure
Use your ruler and pen to mark the dimensions of the three sections on the cardboard.
The tube will be in the shape of a hexagon (6 sides)
Width (all) = 20cm
Length:
Biggest
- Piece = 60cm
- Sides= 10.0cm
Middle
- Piece = 57.6cm
- Sides = 9.6cm
Smallest
- Piece = 55.2cm
- Sides = 9.2cm
Step 2: Cut the Pieces
Place the cardboard on the cutting mat. Use the metal ruler as a guide and carefully cut out the three marked rectangles with the utility knife.
Step 3: Score the Fold Lines
Scoring is making a shallow cut (not all the way through) to allow the cardboard to fold cleanly.
Place the ruler along these six marks, press lightly on the blade and cut along the lines, creating a hinge
Step 4: Paint for Light Isolation
4. Lay the three scored pieces flat. flip the boards, the unscored side will be the interior. Paint the interior fully with black acrylic paint. (Painting the exterior is optional)
The inner surface must be a deep, non-reflective black to prevent any ambient light that enters from bouncing back into your eye.
Step 5: Form the Hexagons
5. Once dry, fold each of the three pieces along the scored lines into the hexagonal prism shape.
Step 6: Glue the Seams
6. Use the hot glue gun to seal the final long seam on each piece, forming the closed tube. Hold the seam firmly until the glue is cool and set. You now have three separate hexagonal tubes.
Step 7: Combine the Tubes
7. Finally:
- Slide the Middle Piece over the smallest piece, aligning the two ends on one side (the viewing end).
- Slide the Biggest Piece (Outer) over the middle piece, aligning the viewing end.
