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Compare Webb's Images to Hubble

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Re: Compare Webb's Images to Hubble

#111

Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed. What am I missing?

The TLDR is that Webb can see much further across the universe (and thus much further back in time) and at higher higher resolution than Hubble, and Webb’s primarily Infrared sensors can see through nebulae, space dust and other obstructions better. There are numerous videos on the differences, but here are some I found pretty good:

1. Scientific American comparing how far back in time Webb can see vs Hubble: https://youtu.be/nBDHqquK_8k&t=2m8s

2. NASA scientist reviewing Webb’s Carina Nebula image, explaining what Webb is unveiling for the first time, and comparing to the same image from Hubble: https://youtu.be/3y6iWi95ypc&t=2m17s

3. Good overview of Webb and its differences from Hubble: https://youtu.be/JzDWpvtDJ9g

Re: Compare Webb's Images to Hubble

#112

For the professional (or former professional) astronomers among us, I will make my somewhat amused observation that what people are most paying attention to is not really the distinguishing features of JWST. People seem most impressed by the apparent increase in resolution of the images, which is not from a certain point of view the hardest thing to do . HST might have done that if its instruments had been of differe…

Also, when comparing the deep field images I don't think it can be stressed enough the difference in exposure time between HST and JWST images (Hubble had a 10x longer exposure time). Many many more distant galaxies would become visible in the JWST image with the much longer exposure time. I look forward to seeing some long-exposure deep field images from JWST!

Re: Compare Webb's Images to Hubble

#113

Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed. What am I missing?

TBH, I don't think the photos were ever going to be that much more groundbreaking to your average person, given the fact that the angular resolution of the telescope is roughly equivalent to the Hubble.

It's got a much bigger mirror, so why is this the case? Well, it's because the Webb works primarily in the longer, infrared part of the spectrum, not the visible. Resolution is related to the diameter of the mirror and the wavelength being studied - the longer the wavelength, the bigger the mirror you need to achieve the same sharpness.

But working in the infrared part of the spectrum means that Webb can look further back into the past, because the oldest light created by the earliest galaxies has redshifted out of the visible spectrum because of the expansion of the universe. So we'll be able to collect and see much older light from much younger galaxies with Webb that Hubble literally cannot detect because of this redshift.

On top of this, infrared, being a longer wavelength than visible light, allows us to see through dust clouds more readily. Notice how many more stars are visible in the Carina Nebula comparison.

Lastly, the Webb has other instruments such as a spectrograph that allows us to determine the chemical composition of distant objects (such as planets). We can point it at an exoplanet and determine, say, if it has water in its atmosphere.

In total, it means marginally better photos for the general public, but a great deal of new data for scientists that should greatly further our understanding of the universe.

Re: Compare Webb's Images to Hubble

#114
post #99

Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed. What am I missing?

With respect, the goal of a major scientific project is not to impress the layperson with pretty pictures.

Though of course the pretty pictures really help with increasing the appetite from the public for spending on projects like this.. and capturing people's imaginations is a necessary part of the long game.

Re: Compare Webb's Images to Hubble

#115

Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed. What am I missing?

[deleted]

Re: Compare Webb's Images to Hubble

#116

Earlier quoted context omitted.

It's hard to look at the Webb images without thinking that there must be life and technology out somewhere else in the stars.

Why does that only come from Webb images? You weren't getting that same sensation looking at the Hubble images before? If that's true, then welcome to the club! It took you a bit longer, but we're happy you're here now. ;P

> Why does that only come from Webb images?

Re-read comment.

Re: Compare Webb's Images to Hubble

#117

Downvote me to hell, but as a person who has zero understanding of what differentiates Hubble from Webb, the pictures alone just aren't doing it for me. I was excited to see something completely new given 30 years and 10 billion dollars and instead I feel like I'm seeing what looks like an enterprise upgrade and feel slightly disappointed. What am I missing?

Detecting alien life has now become reality, JWST can analyze the composition of exoplanet atmosphere. If we can detect any technosignatures, then we made the discovery of the millennia.

Re: Compare Webb's Images to Hubble

#119

Earlier quoted context omitted.

Why does that only come from Webb images? You weren't getting that same sensation looking at the Hubble images before? If that's true, then welcome to the club! It took you a bit longer, but we're happy you're here now. ;P

> Why does that only come from Webb images? Re-read comment.

"It's hard to look at the Webb images without thinking..."

What am I missing?

Re: Compare Webb's Images to Hubble

#120

For the professional (or former professional) astronomers among us, I will make my somewhat amused observation that what people are most paying attention to is not really the distinguishing features of JWST. People seem most impressed by the apparent increase in resolution of the images, which is not from a certain point of view the hardest thing to do . HST might have done that if its instruments had been of differe…

Quoted post unavailable.

> This is so dismissive and insulting. ... I'm sure you were well intentioned, but this comment read all kinds of rude and negative.

Your comment is way, way over the top. Their observation is entirely correct, maybe not in your circles, but certainly it's what I'm also seeing on Facebook and twitter.

Hell, NASA posted "The razor-sharp resolution of the @NASAWebb imagery was enough to bring astrophysicist Jane Rigby to tears."

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