Webb Space Telescope Takes Flight

[Rear_Intruder]

The news said it estimated 13 "Billion" light years

Bloomberg - Are you a robot?

As the universe is so full of galaxys

The news said it estimated 13 "Billion" light years

Bloomberg - Are you a robot?

The deep field views show us that the universe has a lot of stuff in it. As the universe is so full of galaxies. Will any image from 13 billion years ago not be distorted by lensing? Can we ever see something from that far away that its light has not passed close to a strong gravitational field? I tried googling the question but either its not a problem or no one has asked it,

 

[ColdDog]

The deep field views show us that the universe has a lot of stuff in it. As the universe is so full of galaxies. Will any image from 13 billion years ago not be distorted by lensing? Can we ever see something from that far away that its light has not passed close to a strong gravitational field? I tried googling the question but either its not a problem or no one has asked it,

Good question, I have no idea. The cool thing is that we are actually seeing the past, not the present. I'd imagine a lot has happened in 13 billion years - I cant imagine us not seeing any anomalies - in front of or behind - probably more to come on developments there.

 

[Dirtbag_Leader]

Will any image from 13 billion years ago not be distorted by lensing? Can we ever see something from that far away that its light has not passed close to a strong gravitational field?

Actually, I think the answer is 'yes,' and the deep field shot even helps show that. Einstein of course would tell us it's all relative, but here's a part of the shot that I'm pretty sure shows a far-but-not-gravitationally-lensed-galaxy:

The lower orangish galaxy is clearly being lensed and magnified around the brighter whiteish galaxy in the foreground. But just above that in the darker section is that small, dark, redish galaxy. This one is clearly far away because A.) it's quite small and B.) it has lots of redshift, meaning it's moving 'away' from us at a very high rate and thus likely to be further away. And it neither looks distorted by lensing nor is there any obvious large mass between it and the viewpoint, meaning that light appears to have traveled all the way (perhaps not 13B but say maybe 9B years?) from it to Webb's lens more or less uninterrupted! There's a bunch of others like this in the shot too, but I like this one best because of the comparison to clearly lensed orangeish galaxy for comparison!

 

[Bambooza]

Actually, I think the answer is 'yes,' and the deep field shot even helps show that. Einstein of course would tell us it's all relative, but here's a part of the shot that I'm pretty sure shows a far-but-not-gravitationally-lensed-galaxy:
View attachment 23198

This has to be my favorite picture so far as it demonstrates so much.

 

[Rear_Intruder]

I have texted NASA with the same question, (not expecting a reply).
Looking at Dirtbags image I presume that the "lower orangish galaxy " is actually behind the closer one and in fact would be hidden if not for lensing.
The "small, dark, redish galaxy" has nothing between it and us to distort it maybe.
It still seems like a big ask for something that far away not be be obstructed. I do not know if an unobstructed object from 13BLY will be the norm or a rarity. It is the scale of the distance and density of matter that I can not understand.

 

[Radegast74]

As the universe is so full of galaxys


The deep field views show us that the universe has a lot of stuff in it. As the universe is so full of galaxies. Will any image from 13 billion years ago not be distorted by lensing? Can we ever see something from that far away that its light has not passed close to a strong gravitational field? I tried googling the question but either its not a problem or no one has asked it,

Have you tried "Wikipedia-ing" it?

https://en.wikipedia.org/wiki/Gravitational_lens

the TL;DR is:
All light can be bent by large objects/gravitational fields.

"Lensing" only occurs when the light is bent in such a way that it then is refocused...these are usually discovered totally by accident, as you need the right set up for the location, and we can't just change our location...and we don't know what all is out there that can act like a lense, and even if we find one, it isn't guarenteed that what it will "lense" will be of any interest.

Getting back to your original point, "what's the big hairy deal about the Webb telescope," it really is the better scientific gear and purpose-built IR cameras and detectors.

Since the universe is expanding, and the oldest parts are moving away from us, the light is being red-shifted...

Additionally, for objects inside our own galaxy, the amount of dust & junk in the way is harder to see through in the visible spectrum, but light at longer wave-lengths (i.e., the red and infra-red wavelengths) will be less likely to be diffracted or interfered with. There's a reason why we can look at galaxies 13 billion light years away, but we can't see the center of our own galaxy --> space gunk gets in the way! It's the density of all the crap that really casts a blanket, so to speak, in our way.

And if nothing else, the Webb telescope is better than the Hubble because camera tech has gotten a lot better since it launched in (crap) 1990. Do you know what CCD's were like back then?

 

[Rear_Intruder]

Rad, my original point was not "what is the big deal about the (JWST)" It was that the first image reveal was a disappointment to me, a non scientist. (and that the actual show was badly produced by NASA)
For me it was just more of the same, in fact just more detailed views of things already seen.
I'm still hopeful, I want our moneys worth ($10 Billion)
I'm learning a lot about lensing.

 

[NaffNaffBobFace]

Them there imagers looks real perty:

https://twitter.com/i/web/status/1547253198192316418

View: https://twitter.com/th3j35t3r/status/1547253198192316418?s=19

 

[NaffNaffBobFace]

Now the Hubble has been replaced we can use it for it's true purpose... Turning it back on the earth and watching Drive In Movie screens for free!

Admittedly sound doesn't move through space so it's only half the experience... but I think getting extra value out of an obsolete $2 billion telescope is a shrewd move, yo.

 

[ColdDog]

There's a reason why we can look at galaxies 13 billion light years away, but we can't see the center of our own galaxy --> space gunk gets in the way! It's the density of all the crap that really casts a blanket, so to speak, in our way.

Space gunk... what are the odds of our- human made "space gunk" getting in the way of anything in a universe infinitely bigger that our planet earth? Even if disposed 360 degrees around the earth, it is a needle in haystack - meaning that it would really have to be in the way of a telescope which- prolly have better chance of finding life on the moon. "Space gunk" in earth orbit is a totally different thing.

 

[Radegast74]

Rad, my original point was not "what is the big deal about the (JWST)" It was that the first image reveal was a disappointment to me, a non scientist. (and that the actual show was badly produced by NASA)
For me it was just more of the same, in fact just more detailed views of things already seen.
I'm still hopeful, I want our moneys worth ($10 Billion)
I'm learning a lot about lensing.

And the answer is, the real meat of the Webb isn't to produce stunning images in the visible spectrum, it is really to go hunting for more specific targets in the IR spectrum.

Of course, they can manipulate the images they get to look pretty, but, that really isn't the purpose.

 

[Vavrik]

Something interesting, on GitHub for all to enjoy. It's an interactive tool that allows you to do direct comparison between Hubble and Webb using the same images both took. Scroll down to see the choices. Have fun.

Deep Field

 

[Jolly_Green_Giant]

< 5 months has passed >
[ANTICIPATION]

On Monday (I think) NASA is going to hold a news conference to show the first images from the James Webb Telescope, and apparantly, they are going to be stunning:

NASA scientists say images from the Webb telescope nearly brought them to tears

Deep field images of the universe, exoplanet atmospheres, and more to be unveiled.

arstechnica.com

Tears? Really? Holy cow! There's no crying in astronomy, LOL

They did release a test image from their mirror alignments, and OMG! It's full of...GALAXIES! and Nebulae!

Even the Webb telescope’s engineering test images manage to wow

The data was taken to test how well the telescope could stay locked onto a target.

arstechnica.com

(for reference, the 8-10 stars that are in the field of view are the objects with the black centers...)

By way of illustration, this dude took a picture of the same area of the sky from his terrestial 8" telescope, and this is what he was able to see:

View: https://www.youtube.com/watch?v=p1mObQX7NN8


You know what's coming next?

Spoiler: Spoiler!

View attachment 23185

WOOO!

 

[Carlos Spicyweiner]

Meh. The important thing to keep in mind is, the MISC Endeavor will be here sometime in the next 10 years and make the JWST look like an expensive Etch-a-Sketch….BWAAAAAHAAAA!!! Just kidding, as an amateur astronomer, these pictures are stupefyingly beautiful.

 

[Jolly_Green_Giant]

Reading the Hubble telescope releases, the scope had to take much longer measurements to get the same results.

I just wanted to say, I was looking at the hubble ultra deep field and comparing it to the new deep field by webb. What amazed me the most was not the magnificence of the picture itself, but the time it took to produce it. The hubble deep field was a bunch of exposures over the course of a decade. The webb telescope produced an image much clearer and looking much farther, all in less than 2 months. I dont know exactly how long of an exposure they had to use, but it couldnt have been long at all. Were talking days instead of years. Imagine what we will see if we have a decade worth of webb images to stack.


EDIT:

Hubble Ultra-Deep Field - Wikipedia

"A composite of separate exposures taken in 2002 to 2012 with Hubble's Advanced Camera for Surveys and Wide Field Camera 3, it shows some 10,000 galaxies."

 

[Jolly_Green_Giant]

Now the Hubble has been replaced we can use it for it's true purpose... Turning it back on the earth and watching Drive In Movie screens for free!

Just some gee wiz info. Hubble came about because the US National Reconnaissance Office (NRO) commissioned a spy satellite that was pretty much hubble 1.0. When creating the satellite they made two primary mirrors incase they messed one up. The NRO gave this extra mirror to NASA to make their own satellite under the condition it never be pointed at earth, because then if the images were made public, people could find the limits of our spying capabilities.

Have you tried "Wikipedia-ing" it?

https://en.wikipedia.org/wiki/Gravitational_lens

the TL;DR is:
All light can be bent by large objects/gravitational fields.

"Lensing" only occurs when the light is bent in such a way that it then is refocused...these are usually discovered totally by accident, as you need the right set up for the location, and we can't just change our location...and we don't know what all is out there that can act like a lense, and even if we find one, it isn't guarenteed that what it will "lense" will be of any interest.

Getting back to your original point, "what's the big hairy deal about the Webb telescope," it really is the better scientific gear and purpose-built IR cameras and detectors.

Since the universe is expanding, and the oldest parts are moving away from us, the light is being red-shifted...

Additionally, for objects inside our own galaxy, the amount of dust & junk in the way is harder to see through in the visible spectrum, but light at longer wave-lengths (i.e., the red and infra-red wavelengths) will be less likely to be diffracted or interfered with. There's a reason why we can look at galaxies 13 billion light years away, but we can't see the center of our own galaxy --> space gunk gets in the way! It's the density of all the crap that really casts a blanket, so to speak, in our way.

And if nothing else, the Webb telescope is better than the Hubble because camera tech has gotten a lot better since it launched in (crap) 1990. Do you know what CCD's were like back then?

Maybe not for you, but heres something to supplement what you're talking about. Pretty good read.

The Truth About Hubble, JWST, and False Color | NASA Blueshift

 

[NaffNaffBobFace]

Just some gee wiz info. Hubble came about because the US National Reconnaissance Office (NRO) commissioned a spy satellite that was pretty much hubble 1.0. When creating the satellite they made two primary mirrors incase they messed one up. The NRO gave this extra mirror to NASA to make their own satellite under the condition it never be pointed at earth, because then if the images were made public, people could find the limits of our spying capabilities.

Ah, the old "Why buy one when you can have two at twice the price!"

 

[Jolly_Green_Giant]

Ah, the old "Why buy one when you can have two at twice the price!"

Here's another instance of the NRO giving stuff up to NASA. They say the 2 satellites donated are a substantial improvement over Hubble, and both of which the NRO considers obsolete.

2012 National Reconnaissance Office space telescope donation to NASA - Wikipedia

 

[Vavrik]

I just wanted to say, I was looking at the hubble ultra deep field and comparing it to the new deep field by webb. What amazed me the most was not the magnificence of the picture itself, but the time it took to produce it. The hubble deep field was a bunch of exposures over the course of a decade. The webb telescope produced an image much clearer and looking much farther, all in less than 2 months. I dont know exactly how long of an exposure they had to use, but it couldnt have been long at all. Were talking days instead of years. Imagine what we will see if we have a decade worth of webb images to stack.

Just adding to your excellent responses.
JWST took 12.5 hours to take the deep field image. https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-delivers-deepest-infrared-image-of-universe-yet
Also, note that JWST was not focused at 13.1 billion light years, but 4.6 billion light years. They were duplicating an image Hubble had taken ( conjecture: because it showcases the abilities of JWST.)

The main issue with Hubble is that it orbits the Earth, where JWST orbits the sun. Earth orbit means Hubble didn't have a long exposure time on a specific area of the universe during any particular session, so multiple sessions were required. On the other hand, JWST has a continuous view that could last for days, but it is orbiting the sun rather than Earth (and it is orbiting arouind the LaGrange point) so a particular view might need also to take years to get. But it can do a ton of other stuff in the mean time.

:: edit: there was a mess in the second last sentence... I was distracted by what turned out to be a shiny nut.

 

[Jolly_Green_Giant]

Just adding to your excellent responses.
JWST took 12.5 hours to take the deep field image. https://www.nasa.gov/image-feature/goddard/2022/nasa-s-webb-delivers-deepest-infrared-image-of-universe-yet
Also, note that JWST was not focused at 13.1 billion light years, but 4.6 billion light years. They were duplicating an image Hubble had taken ( conjecture: because it showcases the abilities of JWST.)

The main issue with Hubble is that it orbits the Earth, where JWST orbits the sun. Earth orbit means Hubble didn't have a long exposure time on a specific area of the universe during any particular session, so multiple sessions were required. On the other hand, JWST has a continuous view that could last for days, but it too is has to be aware that it is orbiting the sun (and it is orbiting arouind the LaGrange point) so a particular view might need also to take years go get. But it can do a ton of other stuff in the mean time.

Excellent info.