Overview

The "Pi in the Sky" math challenge gives students a chance to take part in recent discoveries and upcoming celestial events, all while using math and pi just like NASA scientists and engineers. In this problem from the 10th set, students use pi to compare the area of the Hubble Space Telescope and Webb Telescope’s primary mirror.

Materials

Background

An illustration shows the 18 hexagonal pieces that make up the primary mirror of the James Webb Space Telescope next to the primary mirror of the Hubble Space Telescope. The James Webb Mirror stands taller with a label that reads 6.5 meters in height, while the Hubble mirror is labled with a diameter of 2.4 meters. Two human figures are shown smaller than the Hubble mirror for comparison.

Image from animation comparing the relative sizes of James Webb's primary mirror to Hubble's primary mirror. Credit: NASA/Goddard Space Flight Center . | › Full animation

Rad Reflection

When NASA launched the Hubble Space Telescope in 1990, scientists hoped that the telescope, with its large mirror and sensitivity to ultraviolet, visible, and near-infrared light, would unlock secrets of the universe from an orbit high above the atmosphere. Indeed, their hope became reality. Hubble’s discoveries, which are made possible in part by its mirror, rewrote astronomy textbooks. In 2022, the next great observatory, the James Webb Space Telescope, began exploring the infrared universe with an even larger mirror from a location beyond the orbit of the Moon. In Rad Reflection, students use pi to gain a new understanding of our ability to peer deep into the cosmos by comparing the area of Hubble’s primary mirror with the one on Webb.

Procedures

Rad Reflection

The James Webb Space Telescope was designed to look back at some of the earliest galaxies in the universe. To capture light from these distant and faint objects, the telescope must be very sensitive. Webb uses 18 hexagonal mirrors that combine to form a massive primary mirror with a surface area of 26.4 m2. This large mirror allows the telescope to collect incredibly faint infrared light and reflect it onto four onboard science instruments, like the Mid-Infrared Instrument, or MIRI. This science instrument can reveal stars hidden within gas and dust clouds and tell scientists about the materials that make up distant galaxies.

Launched in 1990, the Hubble Space Telescope changed our understanding of the universe when it began operations using a primary mirror that had a diameter of just 2.4 meters.

How much bigger is the area of Webb’s primary mirror than Hubble’s?

› Learn more about the James Webb Space Telescope

In the upper left of the image is an illustration of the James Webb Space Telescope. In the lower left is an illustration of the Hubble Space Telescope. To the right of each telescope is an arrow pointing to a face-on view of its primary mirror. Next to the Webb telescope is a primary mirror composed of 18 hexagonal gold-plated mirrors arranged in a roughly circular shape. Above the mirror is text stating the surface area is 26.4 square meters. Next to the Hubble telescope is a round primary mirror with text stating the diameter is 2.4 meters. Both telescopes are in front of an illustrated star field. On the right hand side of the image is a view of space containing stars, spiral galaxies, and elliptical galaxies. Some of the galaxies are warped as a result of gravitational lensing. The text of the Rad Reflection problem is shown on the right.

Image credit: NASA/JPL-Caltech | + Expand image

NASA's Universe of Learning materials are based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, and the Jet Propulsion Laboratory.

Assessment

Illustrated answer key for the Rad Reflection problem.

Image credit: NASA/JPL-Caltech | + Expand image

Download text-only answer key (Google Docs)

Extensions

Participate

Join the conversation and share your Pi Day Challenge answers with @NASAJPL_Edu on social media using the hashtag #NASAPiDayChallenge

Blogs and Features

Related Lessons for Educators

Related Activities for Students

Multimedia

Recursos en español

Facts and Figures

Websites


NASA's Universe of Learning materials are based upon work supported by NASA under award number NNX16AC65A to the Space Telescope Science Institute, working in partnership with Caltech/IPAC, Center for Astrophysics | Harvard & Smithsonian, and the Jet Propulsion Laboratory.