Sorry. That’s a trick question, there are actually a ton of things that every telescope has to have to work properly, but chief among them might be a set of lenses.
Or at least that’s what researchers once thought.
According to engineers working at the University of Colorado, Boulder a new lensless model of telescope could be constructed using a large disk as a diffraction lens that would bend light from a target object and concentrate it on a smaller capturing station tens to hundreds of miles afield.
Named for French naturalist Francois Arago, who first discovered the phenomenon of disk diffraction, the Aragoscope will take his observations and stretch them to their astronomical limits.
As Boulder engineers describe it, light from a target star or exoplanet would be bent around the Aragoscope’s half-mile diameter opaque diffraction disc. As the light crawled around the disc’s edge it would begin to bend and funnel itself towards a small telescope tethered at the appropriate focal distance. As images are resolved they would be beamed to astronomers around the globe where their contents could be deciphered.
“Traditionally, space telescopes have essentially been monolithic pieces of glass like the Hubble Space Telescope,” said CU-Boulder doctoral student Anthony Harness of the Department of Astrophysical and Planetary Sciences, who is working with Cash on the project. “But the heavier the space telescope, the more expensive the cost of the launch. We have found a way to solve that problem by putting large, lightweight optics into space that offer a much higher resolution and lower cost.”
Currently, NASA is only funding the proof-of-concept phase for this project, however, given the savings that would be realized by Boulder’s Aragoscope, the chances of this project getting a green light seem pretty high.
If such a project were to take off it isn’t hard to imagine a glut of similar observatories flung far afield, deep into the darker regions of space. With several Aragoscopes operating in concert, our current dearth of telescopes might become a thing of the past. Then again, we’d probably need to build a few more supercomputers just to crunch all of the data we’d be receiving.
Image Courtesy of University of Colorado - Boulder