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Telescopes

Telescopes are our windows into the hidden universe. With them, astronomers can gather faint light from distant stars and galaxies, peer into the atmospheres of exoplanets, and even detect forms of light invisible to the human eye. In this week’s lecture, we’ll explore how both eyes and cameras capture light, what makes telescopes powerful tools for discovery, and how their different designs—refractors, reflectors, and modern observatories—overcome the limits of human vision.

We’ll also look at how Earth’s atmosphere shapes what we see from the ground, why space-based telescopes like Hubble and JWST are so revolutionary, and how linking multiple telescopes together can unlock extraordinary resolution. By the end, you’ll understand not just how telescopes work, but how they allow us to uncover parts of the cosmos that would otherwise remain hidden.

Watch the Science Lesson

Recording posted 10/22/25!

Do the Assignments

Please download the Student Handout (use the button above) for specific homework and quiz questions assigned for this week.

Homework

Work through the assigned set of review questions, quantitative problems, and quiz questions. 

Space Podcast

Students choose a space-related podcast episode to listen to and write a short summary in their journal. 

Stargazing!

Attend live or virtual stargazing event and record your observations—what you saw, how you identified objects, and what surprised or interested you! These entries help connect you with valuable learning experiences with real astronomers.

Want to know what’s up in your night sky tonight? Use the free Stellarium app and also visit skymaps.com (download the map for your hemisphere) to help you identify three objects and two constellations visible from your location tonight. 

You can also use the Skygazer's Almanac poster (I have one on my wall for the current year, as shown in the video below. If they are sold out for your latitude, please wait until December when they roll out the new posters for the upcoming year.) 

Lab Project Activity

Many stars in the night sky are not single, but part of binary or multiple systems. Some are bright and wide, easy to split with binoculars, while others are so close together that only larger telescopes can separate them. Astronomers use measurements of double stars to determine stellar masses, distances, and the dynamics of star systems.

In this lab, you’ll learn how to locate and measure double stars using Stellarium, calculate the telescope aperture needed to resolve them, and plan your own observing session to track down some of the most famous doubles in the sky.

Supplemental Videos

The videos below are short explanations of topics discussed in class.