Low-cost telescope introduces infrared astronomy to the classroom

Astronomy classes provide a way for students to experience the universe and are often an introduction to physics and science for those who might otherwise not be interested in either. Much of the draw for students is the ability to see the cosmos in different ways, yet most practical demonstrations involve telescopes and sensors that operate in the visible light range.

Padgett et al. describe their technique to build a low-cost telescope operating in the infrared range using a commercial sensor and accessible to undergraduate classrooms. They discuss their construction process along with applications for classroom and observatory use.

The centerpiece of their apparatus is a commercial infrared sensor, which in recent years has increased in resolution and dropped in price, making it practical for classroom use. They coupled this sensor with germanium lenses to make a simple classroom setup and incorporated a telescope mount for outdoor astronomy.

“The coolest thing that we did with it was looking at the moon during a lunar eclipse,” said author Cliff Padgett. “Being able to see that certain craters remained hot well after the rest of the surrounding surface had cooled down was a counterintuitive result and brings up some interesting questions for students.”

The authors could also observe the inner planets with their telescope and identify resistors and other electrical components in the lab from their emitted heat. They hope their demonstration of the setup’s possibilities will encourage other educators to incorporate infrared labs into their own classrooms.

Source: “Thermal infrared astronomy for the introductory laboratory,” by Clifford W. Padgett, William H. Baird, J- Spencer Coile, Wayne M. Johnson, Erin N. Groneck, and Robert A. Rose, American Journal of Physics (2022). The article can be accessed at https://doi.org/10.1119/5.0081072 .