Question

James Webb Space Telescope (JWST) Scavenger Hunt

Instructions: Use trusted sources online (NASA JWST site, NASA videos, or teacher-approved articles) to find the answers. Write short, complete responses.

Part A: Fast Facts (Find & Fill)
What does JWST stand for?

In what year was the James Webb Space Telescope launched?

Where in space does JWST orbit (hint: it’s not around Earth)?

What kind of light does JWST mainly observe?

How wide is JWST’s primary mirror (diameter, approx.)?


Part B: Design & Engineering
Why is JWST’s mirror made of 18 hexagonal segments instead of one big piece?

What material coats the mirrors to help reflect infrared light?

What is the purpose of the sunshield, and how many layers does it have?

Why must JWST stay very cold to work properly?


Part C: Science Goals
Name two types of objects JWST studies (choose from: exoplanets, stars, galaxies, nebulae, etc.).

How does JWST help scientists study exoplanet atmospheres?

What can JWST tell us about the early universe?


Part D: Instruments (Match or Find)
Match each instrument to what it does:
NIRCam → ___________________________
NIRSpec → __________________________
MIRI → _____________________________
FGS/NIRISS → ________________________

Part E: Image Hunt (Observe & Describe)
Find one famous JWST image (e.g., a nebula, galaxy cluster, or exoplanet result). What is the object called?

Describe two details you notice in the image.

What new information did JWST reveal compared to older telescopes?

Answer 1

Part A: Fast Facts
- JWST stands for James Webb Space Telescope.
- It was launched in 2021.
- JWST orbits the Sun near the Sun–Earth L2 (second Lagrange) point, about 1.5 million km from Earth.
- It mainly observes infrared light (near- and mid-infrared).
- The primary mirror is about 6.5 meters in diameter.

Part B: Design & Engineering
- The mirror is made of 18 hexagonal segments so it can fold to fit inside a rocket fairing and then be unfolded and precisely aligned in space; a single-piece mirror that large would be too big and heavy to launch.
- The mirrors are beryllium substrates coated with a thin layer of gold to improve infrared reflectivity.
- The sunshield blocks sunlight (and heat) from the Sun, Earth, and Moon so the telescope stays cold and stable. It has five layers.
- JWST must stay very cold so its own heat doesn’t overwhelm the faint infrared signals it measures; lower temperatures reduce thermal noise in the detectors (MIRI is cooled to a few kelvin, other instruments operate around tens of kelvin).

Part C: Science Goals
- Two types of objects JWST studies: exoplanets and galaxies (it also studies stars, nebulae, star clusters, etc.).
- JWST studies exoplanet atmospheres mostly by spectroscopy during transits and eclipses (measuring starlight filtered through or emitted by an atmosphere) to detect gases, clouds, and temperature structure.
- JWST can observe very distant, highly redshifted galaxies to study the first galaxies and stars, galaxy formation and evolution, and the epoch of reionization — telling us when and how the early universe lit up.

Part D: Instruments (Match)
- NIRCam → Near-Infrared Camera for high-resolution imaging and wavefront sensing.
- NIRSpec → Near-Infrared Spectrograph for multi-object and single-object spectroscopy.
- MIRI → Mid-Infrared Instrument for imaging and spectroscopy in the mid-infrared.
- FGS/NIRISS → Fine Guidance Sensor (for pointing) and NIRISS (science instrument for slitless spectroscopy, exoplanet and high-contrast observations).

Part E: Image Hunt
- Example image: “SMACS J0723.3–7327” (Webb’s First Deep Field).
- Two details: thousands of galaxies of many shapes and colors are visible; stretched arc-like features show gravitational lensing by the foreground galaxy cluster.
- New information revealed: JWST shows much fainter and redder (more distant) galaxies than Hubble could see, reveals fine internal structure in distant galaxies, and provides infrared spectra that let astronomers measure redshifts and physical properties of very early galaxies.