What Will the James Webb Space Telescope See?

Stars, galaxies, planets - oh my! Here’s what NASA’s most powerful space telescope yet has its sights set on in space.

Webb Science Slide 2 by Adolf Schaller for STScINASA

Webb will explore an era...

... that no space telescope has explored before.

Webb’s infrared vision was designed to study every phase of more than 13.5 billion years of cosmic history — starting from about ~200 million years after the big bang, a time period we’ve never studied before.

Webb Science Slide 3 (2006-09-21) by NASA, ESA, and S. Beckwith (STScI) and the HUDF TeamNASA

Webb is designed to see the very first stars and galaxies.

In a process called cosmological redshifting, light is stretched from shorter wavelengths to longer wavelengths as the universe expands. That means light from the very first stars and galaxies reaches us as infrared light — which Webb specializes in!

Spiral Galaxy - JWSTNASA

Webb will examine how galaxies change over time.

The beautiful spiral and elliptical galaxies we’re familiar with did not always look this way. Not only can Webb analyze how galaxies form, interact, and change, but it will even be able to map out their composition and structure.

Hubble's Pillars of Creation in visible lightNASA

Webb will be able to peer through a veil of cosmic dust.

Stars and planets form in clouds of gas and dust. Visible light cannot penetrate these clouds, but infrared light can. As a demonstration, here’s the iconic “Pillars of Creation” taken by the Hubble Space Telescope in visible light...

Hubble's Pillars of Creation in infrared lightNASA

...and here it is again in near-infrared light, also by Hubble. As you can see, a multitude of previously hidden stars were revealed! Webb’s capabilities will allow us to see infrared light from celestial objects in even greater clarity and sensitivity than Hubble.

Exoplanet - JWSTNASA

Webb will study the atmospheres of planets...

... around other stars, or exoplanets. By analyzing the starlight that passes through an exoplanet’s atmosphere (a technique known as transit spectroscopy), Webb can tell us about the molecules and elements in its atmosphere. We could also learn about characteristics of the planet, including its color and weather!


Webb will turn its eye towards Mars and the outer planets.

Webb will study the atmosphere of Mars to gain insights into its past. It will also scan the atmospheres of the gas giants — Jupiter, Saturn, Uranus, and Neptune — to map their weather, temperature, and chemical structure.


Webb will dive into researching ocean worlds.

Two of Webb’s targets, Jupiter’s moon Europa and Saturn’s moon Enceladus, are known as “ocean worlds” because scientists believe they may have liquid oceans beneath their surfaces. Webb will study the plumes of water that have been observed on their surfaces.

Centaurus A galaxyNASA

But that’s not all!

Webb will also see the unexpected and unknown...

Webb will unlock a rich treasure chest of infrared data. While scientists will point Webb at a variety of objects, Webb will also be able to discover things we can’t even imagine at the moment. What else do you think Webb will see?

Credits: All media
The story featured may in some cases have been created by an independent third party and may not always represent the views of the institutions, listed below, who have supplied the content.
Google apps