How Telescopes Work
...Wait, how do they even work?
We use telescopes to look at the whole universe and find new planets! Read below to find out how they work.
How do telescopes work?
All telescopes use convex and concave pieces of glass as lenses to gather light (and other frequencies of electromagnetic radiation depending on the telescope) from the night sky. Using a lens similar to a magnifying glass scientists are able to magnify and project the wavelengths. The resulting image is what we perceive as stars!
The telescopes which are used by NASA and planet hunters are slightly more advanced than your average telescope. For instance, the James Webb telescope has technology which intercepts red and infrared light, and reflects it onto a smaller mirror. The light is then redirected into a receptor which inputs the data to formulate images of the inspected objects. These telescopes that are used by professional planet hunters also have components like a sun-shield, which is meant to keep the cold. They are way bigger than the average telescope, and are designed to be able to fold in on themselves most times.
The TESS telescope is slightly different, in that it uses four different cameras to monitor outer space at all times. It uses the transit method to observe dips in light and movement of potential exoplanets surrounding their stars.
James Webb Telescope
Coronagraphs and Starshade Devices
However, the light from stars is sometimes so overpowering we cannot see orbiting exoplanets. In order to properly view smaller planets, we need to block light! There are two devices that are used to do so, both involving the telescope.
Coronagraphs: These instruments are specifically designed to block out light from stars, so you can view their surroundings and surfaces. Coronagraphs are placed inside telescopes, which blocks the light before it reaches the director. As well, it picks up possible distortions caused by nearby exoplanets, which serve as hints to scientists.
Starshade device: Slightly different than a coronagraph, Starshade devices are usually placed outside the telescope, and is used to block light before it even enters the telescope. They usually produce clearer images of distant stars.
Example of a coronagraph
Spectrographs
A spectrograph passes light coming into a telescope through a tiny hole or slit, which isolates light from a certain area or object. This light is then rebounded by a grating (a surface which diffracts light), and is split into different wavelengths which is then recorded by a detector. Previously, spectrographs have been used to discover stars orbiting outside our solar system, record black holes, and even show massive clouds of ionizing gases!
Process of spectroscopy.