Why all the excitement about the JWST? (2023-1-02) ⬅︎
Why all the excitement about the new James Webb Telescope?
First, a question… have you ever been alongside a road when an emergency vehicle with siren blazing passed you by? If so, you probably noticed how the sound changed to a lower pitch the instant it passed. You can listen here:
This phenomenon is known as a doppler shift. Explanation: sound is made of waves (vibrations) and the
waves in front of the moving vehicle are compressed by its speed while the waves behind the vehicle are stretched
out. We experience this as a sudden drop in pitch as the vehicle passes.
What does this have to do with the James Webb Space Telescope? Plenty, actually….
In our Universe, stars and galaxies are moving and giving off energy in waves that can be compressed or stretched
also based on how quickly the object is moving toward or away from us.
A lot of the energy is given off as visible light. We’ve learned that, for the furthest objects in the Universe, the energy waves can be stretched so much that the visible light is no longer visible — it becomes infrared energy instead.
What this means is that telescopes designed for visible light, like the Hubble Space Telescope (HST), are limited in how far they can see. The new James Webb Space Telescope (JWST), because it has been designed specifically for infrared, can see much deeper into the Universe.
But there is much more to the JWST that just seeing further into space. Space is so vast that it
takes enormous amounts of time for energy
from distant objects to reach us. So when it does reach us, it doesn’t reveal what the object looks like
now, but what it looked like at the time the journey began -- way back to the early formation of the
Universe. Think about it…. every telescope is like a time machine and the JWST is able look further back in time than any telescope before.
And there’s more… our Milky Way Galaxy has enormous clouds, or nebulas, within which stars and planets are
being born. These nebulas are so thick that they block visible light but they don’t block
infrared. This means that the JWST is able to look into them and reveal star and planet formation in progress.
One more thing… because the JWST's mirror assembly is so much larger than the HST's mirror, its ability to resolve fine details is far greater. It may become possible to detect the signatures of life on distant worlds.
So why all the excitement? The JWST is a huge leap in humanity's abilities to understand the birth of our Universe and Earth, and to learn if there is life elsewhere. If all goes well, the images and knowledge that this telescope reveals in the coming years may be astounding.... like the images above that have come from the first year alone!
