Telescopes

Watch the video Telescopes, where I take you on a field trip to my favorite telescope. Along the way, we’ll see exactly what makes telescopes work the way they do.
Read 6.1 Telescopes to understand how telescopes collect and focus light from astronomical sources and the differences between refracting and reflecting telescopes.
Watch The Evolution of Telescope Mirrors to learn how professional astronomers and engineers are building enormous telescopes with cutting-edge technology.
Explore 6.2 Telescopes Today to discover advancements in telescope technology since 1990, including the development of lightweight mirrors and the use of adaptive optics to counteract atmospheric turbulence.
The “Extremely Large Telescope” (ELT) referenced in the previous video and reading seems so big that it would never actually be built in real life, right? WRONG! - How dare you doubt the willpower of astronomers! It is currently under construction as you can see from this 2023 update video.
Our atmosphere is like a blurry curtain that we must look through to observe the universe. Advanced systems like “adaptive optics” allow telescope mirrors to actively correct for distortions in the atmosphere, but as Figure 5.6 from our textbook illustrated, the earth’s atmosphere is only transparent in a small portion of the full EM spectrum. (This is a good thing for us - the atmosphere protects us from getting baked by x-rays and UV from space, but it is bad for astronomers.) Space telescopes, therefore, help us in two ways: 1) they get our telescope above the blurring effects of the atmosphere (allowing for better clarity in the images), and 2) they allow us to make observations in parts of the EM spectrum that are not visible from the surface of the earth.
Read 6.5 Observations outside Earth’s Atmosphere to explore the challenges and benefits of observing in different bands of the spectrum from outside Earth’s atmosphere, including the use of orbiting observatories for infrared, ultraviolet, X-ray, and gamma-ray observations.
The James Webb Space Telescope (JWST) represents the current state-of-the-art in space observatories. New discoveries are arriving weekly, and it is exciting to follow along. A search of “JWST” on Google or YouTube could easily send you down a rabbit hole for several hours. Take a quick look back at the JWST Mission Trailer, marvel at its incredible engineering, and check out the latest updates on the JWST mission website.