Document Type

Article

Publication Date

2022

DOI

10.1119/10.0010410

Publication Title

The Physics Teacher

Volume

60

Issue

5

Pages

A390-391

Abstract

[Introduction] Question: If the James Webb Space Telescope could be turned to face the Earth, how small an object could it resolve? How does that compare to the Hubble Space Telescope?.

To answer this, we need to know the location of the JWST, its size, and the wavelengths it can image. (This is one of those Fermi questions where we're not really estimating, but we are calculating unusual order-of-magnitude answers.) The JWST is orbiting the Earth and Sun at the second Lagrange point, L2, which is located 1.5 × 10⁶ km beyond the Earth (so that the Sun, Earth and JWST are in line)...

Question 2: JWST2 Question: How much heat from the Earth is blocked by the Sun and Earth shade of the James Webb Space Telescope?.

To answer this question, we need to know the distance from Earth to the JWST and the area of the JWST. We also need to estimate heat radiated by the Earth. The JWST is 1.5 million km from Earth and has a diameter of 6.5 m. That's the easy part...

Rights

© Copyright 2022 AIP Publishing LLC.

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in

Weinstein, L. (2022). Solutions for Fermi questions, May 2022. The Physics Teacher, 60(5), A390-A391. 

and may be found at https://doi.org/10.1119/10.0010410

Original Publication Citation

Weinstein, L. (2022). Solutions for Fermi questions, May 2022. The Physics Teacher, 60(5), A390-A391. https://doi.org/10.1119/10.0010410

ORCID

0000-0001-5416-2900 (Weinstein)

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