The Extremely Large Telescope (ELT) will be the world’s largest optical/near-infrared telescope. It is under construction on top of a mountain named Cerro Armazones in the Atacama Desert of northern Chile. Now you can build your own slightly smaller, incredibly lower cost version of your own ELT – using paper.
As the instructions say, all you need is some A4 paper, a paper cutter or scissors, glue (and optionally a ruler and a cutting board). The estimated assembly time for the paper version is 15 hours, considerably less time than the real version, estimated to take about 10 years.
One very cool feature of the paper version is that the dome of the ELT paper model will rotate, just like the real one. If you do build one, the European Southern Observatory (ESO) encourages you to share your models on social media using #BiggestEyeOnTheSky.
The real ELT will consist of a reflecting telescope with a 39.3-meter-diameter (130-foot) segmented primary mirror, with 798 hexagonal elements that all work together. It also has a 4.2 m (14 ft) diameter secondary mirror. The observatory aims to gather 100 million times more light than the human eye, 13 times more light than the largest optical telescopes, and be able to correct for atmospheric distortion with adaptive optics and eight laser guide star units. It also has multiple science instruments. The telescope’s construction is estimated to be completed by 2028.
Paper models are fun and inexpensive. Personally, I’ve built a paper 1 meter (3 foot)-tall Saturn V and a Hubble Space Telescope. NASA has many of their spacecraft available with paper model instructions here.