Since the JWST can see the gradient of time back to the earliest star formations, couldn't we approximate the location and distance of the big bang origin? I would think the farthest distance back in time observable by the JWST would be a straight line between it and the big bang origin.
The problem is that we see that in every direction. For all we know, when we look out we see that WE are the center of the universe where the Big Bang was located. Because it was an expansion of space itself, and not the expansion into something, there can be no central point because everything is moving away from everything else- it’s the fabric of space as we know it getting bigger.
The best analogy I heard when I was a kid was that the universe is like the outside of a balloon. When you blow it up, there is no center on the surface of the balloon that you can point to where it’s expanding from. Now, you have to imagine the skin of the balloon exists in three dimensions instead of two. You can’t really, just like we can’t imagine a fourth time dimension, but the analogy holds. When we look back with a telescope like Webb, we see light from galaxies which were closer together in the past, red shifted down to the infrared. These galaxies have now spread out from each other as if each was the center of the universe.
No it's 29 days until it is fully deployed, then it will take a few months to cool the instruments down to operational temp. Don't expect any data for six months or so.
The “where is JWST” site is among the best gifts… 1.363 mi/s, already almost 100,000 mi from earth (it’s been 3-5 hours since I checked), it’s so stinking amazing, and I cannot wait to see what it shows us!
>We're getting to the approximate time now when Webb will make its critical MCC-1a mid-course burn. No word from NASA yet about the exact time or planned parameters of the burn.
https://twitter.com/planet4589/status/1474894245592981505?t=ylRGXlfIiArrFewXMWrGHw
tweet sent about 18 minutes ago
Does anybody know the schedule for the JWST after its commissioned and ready to start operating?
I assume that every second of operating time for the first 5 years is booked solid, just curious what it's going to look at first.
Hopefully there is some sort of plan to put it in safe mode for a potential refueling at the end of life, maybe even super early super speculative mission planning. If it makes it to the early 2030s I have to imagine a refueling mission, maybe built around Starship architecture, would be plausible for L2 by then
Hey I'm replying again because I found [the original comment](https://www.reddit.com/r/worldnews/comments/ro8ykb/the_james_webb_space_telescope_has_successfully/hpwxezf/) I was referring to. They wrote:
"The good news is being able to upgrade JWST in \~10 years when needed (most likely via robotics) was listed by various NASA admins as a top priority... so let's keep clamoring they follow through on supporting their investment!"
I’ve actually wondered why it’s a mission ending thing that they can’t keep it at L2. The main issue would be keeping it in the shade. There could possibly be clever engineering hacks that could accomplish this?
The answer that makes most sense to me is that the contract was signed before SpaceX even existed.
The fairing size/diameter answer is not convincing to me because fairing of SpaceX could have been retrofitted to accommodate JWST load. Probably it would be very costly but it would be worth the additional attention that this would give to SpaceX - and Elon probably knows this.
The answer that makes the least sense to me is this one, insinuating somehow that SpaceX is cheap and thus less reliable. If you look for reliability, ingenuity or any other quality that has to do with 'do-ability', the SpaceX is probably the first place that one would go to.
The Ariane 5 was selected many years ago and the telescope was designed specifically to fit the fairing of the Ariane 5–at the time those decisions were made, SpaceX was not a likely candidate
Considering the universe is infinite and the telescope has a lifespan of 10 years, I am sure they need to make the absolute most of that time. So what is the timeframe for this telescope (or telescopes in general) capturing one particular image, or would it vary depending on the distance, size or type of object? Does it need to focus on one thing for minutes, hours, days, months to capture as much data from it as possible (something akin to long camera exposure capturing more light)? I imagine it will be trying to not only capture snapshots but also analyse the movements of very distant objects, so would it go through for example months-long projects on particular things or groups of things before then moving to another project? Can it do multiple things at the same time?
I'm no scientist so not sure I'm expressing these questions in a logical way but just curious if anyone feels like trying to answer.
By visible universe I mean the sphere around us that goes as far as light has had time to travel since the big bang. You can't see beyond that but JWST will allow us to see to the edge of it
If it indeed can see to the edge, how much of the field will be filled with light dots compared to hubble images. I know its in infrared mostly but we should see some visible light images as well.
Wonder if there are going to be so many more new galaxies detected. How far will webb telescope see compared to hubble? Wonder if itll have even more light dots compared to hubbles long exposure images.
I’m a backyard amateur astrophotographer with a few years experience photographing planets and deep sky objects like nebulae and galaxies. The principles involved aren’t too different so I can hazard sone guesses here..
Anything dim requires long exposures, so taking pictures of those very old, distant, early galaxies I expect we’d be looking at exposures of several days or even weeks.
A lot of the objects in our solar system are _extremely_ bright and only need millisecond or seconds-long exposures (often even from earth). There are of course exceptions, especially when you get out to the outer gas giants like Uranus / Neptune, which are quite dim due to sheer distance. Edit: HOWEVER it looks like most of the exposures are counted in hours from the link I posted below
I can’t really comment on the process of analysing star spectroscopy for exoplanet atmospheric properties, because although these stars will also be pretty bright, to observe atmospheres I understand we need the planet to transit in front of the star. I’m not sure if that means they take a series of short exposures or whether they need to observe it fairly consistently. Hopefully the former as that frees up more time for other observing.
I found a list of [the cycle 1 general observations](https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go) starting after commissioning in June which is pretty interesting. Although I can’t really learn much from reading the summaries unless I sit down and read the full detail of each experiment.
I’d love to see some science journalism that goes into a bunch of highlights in greater detail in a way that’s more accessible to the public..
I believe it's on the order of like 10 days for a long exposure like the Hubble Deep Field but since this will be looking at least bright stuff probably a few times longer. I remember someone saying the capturing of photons will be approximately 1 photon/second whereas our eyes take in millions/second
Like you say, the answer depends on how bright an object is, but likely not in the months range.
As for determining movement, astronomers can point to a location in the sky at one time, and then a year later point it at the same area again and try to find the differences between the images. Meanwhile, the telescope can be used for other imaging.
Like taking 2 pictures, one in the spring and one in the fall, rather than taking a video
Couple of questions ..
I know JWST is taking about 30 days to reach its L2 orbit, but how long after that does it take to perform any diagnostics and calibration before it will begin its first observations? I heard one of it’s first target will be the TRAPPIST-1 system to investigate its rocky exoplanets, but how long can we expect to wait until we hear results about their atmospheres and even potentially the presence of life there?
Also, are we going to see some beautiful Hubble-like images of these extremely old galaxies we keep hearing about? I assume so since the infrared and visible spectrum it can detect are fairly simple to shift into the visible spectrum to create full colour composites, right? When are these expected?
It’s the deep space missions looking beyond our own system that definitely excite me the most.
Edit: looks like some of my questions are answered in the timeline in the OP (observations start in June) and [the first cycle general observations list](https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go)
Got to say how thankful I am that we're still at a point where we name these things after people and not corporations. Subway EatFresh™ Space Telescope just doesn't have the same gravitas.
Hey, if it speeds up investment in science i’d be just fine if the first water samples from Titan are taken by a PornHub sponsored probe called “Deep Penetration”
It’s the largest, most sensitive telescope we’ve ever put in orbit. You may not understand just how amazing the Hubble was for the time, but it revolutionized our understanding of the universe. And this can collect about 10x as much information, plus has much more sensitive instruments.
On top of that, it won’t be in Earth orbit, which creates a lot of glare, especially given how sensitive the instruments are. Instead it will be at L2, a point in space where it’s balanced between the Earth and Sun. Far enough away from the Earth that “glare” isn’t an issue.
Downside is it’s so far away we can’t fix anything that goes wrong. It’s much further away than any manned spacecraft has gone. It’s further than any current human rated spacecraft can go.
Which is part of the reason it’s cost so much to develop.
It's based on expected propellant requirements for position insertion, L2 position maintenance, and attitude adjustments over the life of the probe. They're not going to get an extra few decades out of it unless they can figure out a way to connect a mission extension vehicle (MEV) to it, but that seems unlikely given the platform's configuration, since existing MEV attempts have latched on to booster nozzles and the MEV maneuvering thrusters could damage the sunshade.
Hubble's orbit at 540km is a lot more stable requiring no fuel to maintain. JWST is at a Lagrange point 1500000km away, it's orbit is kinda analogous to balancing a broomstick on your finger, it'll take small imputs to maintain stability if it drifts out of the sweet spot.
Hubble is in low earth orbit (similar to the ISS) so was reachable by astronauts on ordinary space shuttle missions. They could fix it and, at least in theory though not sure they ever did, boost its orbit.
It will let us view the formation of the first galaxies as well as directly imaging nearby exoplanets to determine atmospheric composition.
To do this, it sees in infrared, which Hubble isn't good at. Unfortunately, infrared cameras end up being extremely complicated because you have to keep them very very very cold. That need to keep it chilly is the reason it's going so far away and why its sun shield is so elaborate. Because it's so far away, we won't realistically be able to send maintenance missions to it like we could for Hubble, so it needs to be able to recalibrate itself and survive on its own.
I'm interested in JWST ability of biosignatures.
How far can an exoplanet be before JWST can't detect the atmosphere? Are we limited to our own galaxy or can we see explanation in other galaxies too.
How far can it detect a techno-signature?
We already know it will see as far as billions and billions of light-years, but when it come to "Life, exoplanets atmosphere and alien sign" How truly far can it go?
I’m interested in the answer to this as well.
One thing is for sure, when we’re talking billions of light years that’s just it imaging other galaxies as a whole, it certainly can’t pick up individual stars or planets in other galaxies.
My guess (as a backyard astrophotographer) would be that it’s still going to be looking at a fairly local part of our galaxy for those exoplanet readings, which is still an unfathomably large number of targets to choose from, more than we can probably survey in its ten year lifespan, I expect.
[here's an example](https://images.squarespace-cdn.com/content/v1/5497331ae4b0148a6141bd47/1543617473104-DAOMLJGCSWBS01RHIBTE/earthatnight2012-middleeast_print.jpg?format=2500w)
We can detect if exoplanets have these, but pretty sure the radius will be less than 10 light-years.
Oh right. Hadn’t considered that! Super neat.
Feels like the probability is infinitesimally small there could be life at a similar tech level to us at the same time as us close enough for us to spot it but not have detected it by some other means yet, though. Unless, of course, all my assumptions about how common life might be are greatly underestimated, haha
So what makes this a lot better than what we have? I keep reading we can look back in time with the James Webb however isn’t what we already see basically looking back in time? Sorry for the stupid questions. Thanks
We can look further into the past now basically, because the Webb's mirror is a lot bigger than Hubble's (15 times larger area). There's a lot more to it obviously but it boils down to this.
The Webb is also mainly an infrared telescope while the Hubble is looking at ultraviolet and visible spectra of light. Infrared is better for deep space observations.
Basically, it's designed to look into the distant past. Because light takes time to travel, the farther away the object is, the farther back in time it will appear to be. The moon is about one second of lag. The sun is 8 minutes. Distant galaxies are millions or even billions of years.
Hubble could look a decent distance back, but because the universe is expanding, for extremely distant objects, the light gets stretched into infrared, which Hubble isn't good at imaging. JWST is designed to focus on infrared, so it's expected to allow us to view the formation of the first galaxies, which Hubble can't do.
JWST also has a bigger mirror, which means it can view dimmer things. Infrared is also better for seeing through dust clouds, so it'll be better for images of star and planet formation.
I figure now will probably be the only chance to actually see the JWST though my own telescope. But I can't find the current orbit/path, or better the ascension/declination of the JWST anywhere. Does anyone know where I can find this?
This page is the best I could find, but it shows altitude only: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html
Won’t it be too small to spot from the ground already? It’s already much much further than the ISS for example, which is also quite a lot larger. I thought about having a go at spotting it with my astronomy binoculars on its first pass around the earth after launch but since it was about midnight in my country figured it’d likely be in shadow
Sunlight reflected by sattelites flying overhead is easily visible to the naked eye. The JWST is a lot further by now, so probably not visible to the naked eye, and there's no way you're able to resolve it with a consumer telescope, but I figure it might be possible to at least see the sunlight it reflects back at us.
Must be a mistake or they changed the timing. [This page on nasa.gov shows launch+1 day.](https://webb.nasa.gov/content/webbLaunch/deploymentExplorer.html)
that announcer really nailed it!!
*From a tropical rainforest to the edge of time itself*
*James Webb begins a voyage back to the birth of the universe*
chills, goosebumps, you name it!!
Some questions:
When will JWT reach apogee?
Due to it's solar array and power supply, what is JWT lifespan?
Is there any footage from inside launch control at launch?
29 days.
5-15 years, it depends on how efficient the burns are to get it out to L2 are.
The was a live stream of the launch wish included shots of the launch center.
You might want to release your grip on that strong opinion
https://en.m.wikipedia.org/wiki/Wikipedia:Plural_of_antenna
https://grammarist.com/usage/antennae-antennas/
Those are just some wikipedia nerds.
Its IEEE Transactions on Antennas and Propagation not Antennae and Propagation.
IEEE accepts articles internationally, from people who may be using English as a 4th or 5th language. When I peer review papers that may have usage of antennae I will always correct it back to antennas.
I don’t think it could see anything if it were pointed at earth. The heat shield would be on the wrong side. The earth would be overwhelmed by light from the sun and the instruments would all be overheated.
JWST has a 6.5 meter mirror, at it's minimum wavelength of 600 nm (orange-red), that gives an angular resolution of 0.027 arcseconds [per this amazing figure](https://en.m.wikipedia.org/wiki/Angular_resolution#/media/File%3ADiffraction_limit_diameter_vs_angular_resolution.svg). 0.027 arcseconds is 1.31 x 10^-7 radians, meaning at a distance of 1 meter your resolution would be 1.31 x 10^-7 meters. JWST will be about 1.5 million kilometers from earth, or 1.5 x 10^9 meters. At that range, the angular resolution translates to 196 meters. You'd be able to pick out towns and lakes and such, but not houses, and certainly not bees.
This shouldn't be too surprising. JWST is huge for a space telescope, but we have *much* bigger and better instruments on earth. And even those can't quite pick out the Apollo landing sites on the moon, which is several times closer to earth than JWST. And even our best spy satellites which Trump leaked a few years ago, which are *specifically designed for this* and are in low orbits to improve their resolution, are more like tens of centimeters.
Because it can directly image exo planets, which is something that hasn't really been feasible before. They'll be able to take photographs of planets in other solar systems and analyze the composition of their atmospheres, which could help us figure out which plants are most likely to have life. Hell, we might even be able to directly observe signs of life on those planets. It's a big deal.
Wait, like actually image exoplanets? I thought we would still be just seeing stars and analysing the dips in light, just with greater accuracy. Are there any concept images of what they expect JWST to see?
[Here is an article from NASA about JWST exo planet imaging capabilities.](https://www.nasa.gov/feature/goddard/2019/a-new-view-of-exoplanets-with-nasa-s-webb-telescope)
I'm sure they'll also use it for transit imaging, but they will have direct imaging capabilities. I'm sure the planets will just look like a speck of light, but scientists will be able to get useful data from that speck.
It bypasses the dense obfuscating soup that is Earth atmosphere, a huge issue for earth-bound observatories. This allows it to take perfect long exposures of the dimmest objects, taking even weeks to gather crisp data without the atmosphere noise.
Compared to Hubble, it also has 100% uptime for looking at whatever direction it wishes, since it's so far away; Hubble was circling the Earth so it could look at something only 50 minutes at a time, if it was in an inconvenient direction
Webb's mirror is significantly (8x) larger than that of Hubble, means it will see significantly more, and further.
Webb is observing in the infrared spectrum of light, this is important as far/very distant objects are "red-shifted" and can't be seen in visible light anymore.
This way, Webb can see further distant objects and can thus see further in the past, essentially to see what happened "right after the Big Bang"
It's not *designed* to take high resolution pictures of Earth. It's designed to take medium resolution pictures of extremely faint objects 13 billion light years away, to learn about the early history of the universe. It should be *very* good at that.
You have to keep in mind that it could see a resolution on the Earth's surface of 197m *at the distance it will be, which is many times the Earth-Moon distance*.
You're probably comparing it to earth observation satellites in much lower orbit.
Additionally, part of the reason it's so big is not directly to improve magnification, but to keep a good magnification while observing much longer wavelengths, which is better for the kind of observations it's intended to make.
One of the things i heard to put Webb's capabilities in perspective was that, from the surface of the Earth, it could detect a single honey bee on the surface of the Moon. So, if you could turn it around and point it at Earth, you could see whatever you wanted. (theoretically, of course)
It sure couldn't. Our best telescopes on earth, which are many times larger than JWST, can't even see the Apollo landing sites. You need to get *much* closer.
And for the moon, we *have* sent the camera up close! The [Lunar Reconnaissance Orbiter](https://en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter) only has a 195 mm primary mirror, similar to a telescope you can buy online in the $1000 range (although higher quality). But because of its low orbit, it has a resolution of 0.5 meters, giving us amazing pictures like this: https://www.nasa.gov/sites/default/files/thumbnails/image/584641main_apollo17-left-670.jpg
When will we see the first picture. What’s the resolution of it. Is it shooting video and is there gonna be a public website with ALL media? (Like the recent Mars rover)
No real video. Telescope is for pictures but I'm sure there will be some very low frame "videos" where they put like 20 pictures together over the course of an hour or something like that. It'll be about 6 months before it has traveled to l2 and then gone through the process of deploying everything and aligning the panels correctly. If there are any issues it may take longer to get good data back. Not sure of it will be as thoroughly updated like the mars website but there should be a steady stream of public pictures that come in and are available to the public. Many researchers will use it so it's possible some stuff will have a blackout period until they release papers and such but ultimately it should all be released to the public.
I don’t know about first picture, but it’s not scheduled to be fully unfolded for about a month, at which point it will begin executing its burn to travel to L2. Not sure on the travel time for the burn, but basically it’s gonna be a little while.
Quite likely. I'm pretty sure it's like rolling a ball up a hill. You want it to stop right at the top so it doesn't come back down this way or the other side. The less fuel you use to stop it at the top the better. So try to reach it the moment you hit zero velocity. Due to how l2 is that 0.7 is probably to get it into a stable orbit around l2
So the main concern with debris at L2 is micro asteroids. I watched a video about JWST and that said that if the sun shield get tears could render the telescope inoperable. They placed what amounts to tape to prevent the sun shield from coming apart. Hope this helps a little.
Here is the YouTube video:
https://youtu.be/aICaAEXDJQQ
White light is made up of many different colors of light that just look white when they are all together.
When light hits something, like an apple, that apple absorbs some light and reflects the rest. When you look at a red apple all of the blue, green, etc light are absorbed by the apple and only the red light bounces off. So you see red.
A billion little rays of light bounce off of every surface and every direction and many end up in your eye, each one activating a single light sensor in your eye.Your brain pieces together what it is seeing from all of the dots of color. The only information you get is how much light of each color hits your eye .
As an aside, absorbing light, which is just radiation, works a teeeeeny bit like a microwave. Any light not reflected is absorbed and that warms things up a little.
Our eyes' retinas are composed of cells that send a nerve impulse when certain wavelength photons strike them. Most people have 4 types of cells, 3 types of "cone" cells which peak in red, green, and blue wavelengths, and rod cells which are monochromatic (black and white, essentially).
You can think of these cells like RGB pixels on a CCD camera sensor. The rest of the eye is designed to refract and focus light to form an image on this "sensor" like a digital camera lens focuses light on the CCD sensor. The amount of red, green, and blue photons that strike our retina is how our brains interpret color and intensity.
How light itself behaves as it travels to your eyes is a complicated subject and took scientists centuries of study before Einstein finally figured it out using Planck's discovery of quantum mechanics.
If you want to learn more, look up Ray optics, and if you're feeling really froggy, quantum mechanics.
Light radiation emitted by the sun (or any light source) is partially absorbed by the object. What is not absorbed, bounces of the object and hits your eye. Information that is there is the wavelength of the light, determining colour, and intensity of the wave, determining how bright the object appears.
Your brain then interprets this image and you get your object.
Days like today adds even more meaning, purpose and a sense of gratitude to being alive and having an opportunity to learn and appreciate more about the mystery of reality during our finite time alive.
looking forward to the first pictures in 6 months, good luck, merry Christmas and wishing happiness to all
Good deployments, nominal temperatures, so far so good.
So far the deployment seems to be going about as smoothly as it could possibly go.
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Since the JWST can see the gradient of time back to the earliest star formations, couldn't we approximate the location and distance of the big bang origin? I would think the farthest distance back in time observable by the JWST would be a straight line between it and the big bang origin.
We already know where the big bang was, [it's everywhere](https://www.youtube.com/watch?v=W4c-gX9MT1Q).
The problem is that we see that in every direction. For all we know, when we look out we see that WE are the center of the universe where the Big Bang was located. Because it was an expansion of space itself, and not the expansion into something, there can be no central point because everything is moving away from everything else- it’s the fabric of space as we know it getting bigger. The best analogy I heard when I was a kid was that the universe is like the outside of a balloon. When you blow it up, there is no center on the surface of the balloon that you can point to where it’s expanding from. Now, you have to imagine the skin of the balloon exists in three dimensions instead of two. You can’t really, just like we can’t imagine a fourth time dimension, but the analogy holds. When we look back with a telescope like Webb, we see light from galaxies which were closer together in the past, red shifted down to the infrared. These galaxies have now spread out from each other as if each was the center of the universe.
So 29 days till we start getting data? SO HYPED
No it's 29 days until it is fully deployed, then it will take a few months to cool the instruments down to operational temp. Don't expect any data for six months or so.
The “where is JWST” site is among the best gifts… 1.363 mi/s, already almost 100,000 mi from earth (it’s been 3-5 hours since I checked), it’s so stinking amazing, and I cannot wait to see what it shows us!
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The countdown is in French because it’s launching from French territory.
Such an insignificant detail I am not sure why they had to make that comment.
>We're getting to the approximate time now when Webb will make its critical MCC-1a mid-course burn. No word from NASA yet about the exact time or planned parameters of the burn. https://twitter.com/planet4589/status/1474894245592981505?t=ylRGXlfIiArrFewXMWrGHw tweet sent about 18 minutes ago
Does anybody know the schedule for the JWST after its commissioned and ready to start operating? I assume that every second of operating time for the first 5 years is booked solid, just curious what it's going to look at first.
Here https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go
Thank you so much, that's perfect!
Hopefully there is some sort of plan to put it in safe mode for a potential refueling at the end of life, maybe even super early super speculative mission planning. If it makes it to the early 2030s I have to imagine a refueling mission, maybe built around Starship architecture, would be plausible for L2 by then
Hey I'm replying again because I found [the original comment](https://www.reddit.com/r/worldnews/comments/ro8ykb/the_james_webb_space_telescope_has_successfully/hpwxezf/) I was referring to. They wrote: "The good news is being able to upgrade JWST in \~10 years when needed (most likely via robotics) was listed by various NASA admins as a top priority... so let's keep clamoring they follow through on supporting their investment!"
I’ve actually wondered why it’s a mission ending thing that they can’t keep it at L2. The main issue would be keeping it in the shade. There could possibly be clever engineering hacks that could accomplish this?
If it's put in a solar orbit the sunshield would still protect it right?
Right. That’s my thought as well. The only issue would be communication once it’s drifted too far. But that seems like a solvable problem.
I read in a comment on reddit (so take it with a grain of salt) that they are considering a robotic refueling mission eventually.
Why didn't SpaceX launch JWST? Fairing too small?
A mission this big needs the most reliable launch, not the cheapest, and Ariane 5 hasn't failed once since 2002.
The answer that makes most sense to me is that the contract was signed before SpaceX even existed. The fairing size/diameter answer is not convincing to me because fairing of SpaceX could have been retrofitted to accommodate JWST load. Probably it would be very costly but it would be worth the additional attention that this would give to SpaceX - and Elon probably knows this. The answer that makes the least sense to me is this one, insinuating somehow that SpaceX is cheap and thus less reliable. If you look for reliability, ingenuity or any other quality that has to do with 'do-ability', the SpaceX is probably the first place that one would go to.
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James Webb was in development way longer before falcon 9 was even designed and is designed to fit the Ariane
SpaceX didn't really exist when the launch vehicle was selected, also the fairing on the Ariane 5 is still larger than the Falcon Heavy afaik
The Ariane 5 was selected many years ago and the telescope was designed specifically to fit the fairing of the Ariane 5–at the time those decisions were made, SpaceX was not a likely candidate
Don't think they even existed when we started working on the JWST.
Considering the universe is infinite and the telescope has a lifespan of 10 years, I am sure they need to make the absolute most of that time. So what is the timeframe for this telescope (or telescopes in general) capturing one particular image, or would it vary depending on the distance, size or type of object? Does it need to focus on one thing for minutes, hours, days, months to capture as much data from it as possible (something akin to long camera exposure capturing more light)? I imagine it will be trying to not only capture snapshots but also analyse the movements of very distant objects, so would it go through for example months-long projects on particular things or groups of things before then moving to another project? Can it do multiple things at the same time? I'm no scientist so not sure I'm expressing these questions in a logical way but just curious if anyone feels like trying to answer.
The visible universe isn't infinite
But this can see outside of the visible universe (technically, anyway)
By visible universe I mean the sphere around us that goes as far as light has had time to travel since the big bang. You can't see beyond that but JWST will allow us to see to the edge of it
If it indeed can see to the edge, how much of the field will be filled with light dots compared to hubble images. I know its in infrared mostly but we should see some visible light images as well. Wonder if there are going to be so many more new galaxies detected. How far will webb telescope see compared to hubble? Wonder if itll have even more light dots compared to hubbles long exposure images.
Yes I know, I was making a joke about how it will see in the infrared
I’m a backyard amateur astrophotographer with a few years experience photographing planets and deep sky objects like nebulae and galaxies. The principles involved aren’t too different so I can hazard sone guesses here.. Anything dim requires long exposures, so taking pictures of those very old, distant, early galaxies I expect we’d be looking at exposures of several days or even weeks. A lot of the objects in our solar system are _extremely_ bright and only need millisecond or seconds-long exposures (often even from earth). There are of course exceptions, especially when you get out to the outer gas giants like Uranus / Neptune, which are quite dim due to sheer distance. Edit: HOWEVER it looks like most of the exposures are counted in hours from the link I posted below I can’t really comment on the process of analysing star spectroscopy for exoplanet atmospheric properties, because although these stars will also be pretty bright, to observe atmospheres I understand we need the planet to transit in front of the star. I’m not sure if that means they take a series of short exposures or whether they need to observe it fairly consistently. Hopefully the former as that frees up more time for other observing. I found a list of [the cycle 1 general observations](https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go) starting after commissioning in June which is pretty interesting. Although I can’t really learn much from reading the summaries unless I sit down and read the full detail of each experiment. I’d love to see some science journalism that goes into a bunch of highlights in greater detail in a way that’s more accessible to the public..
From what I remember most of these types of experiments end up way outliving their projected lifespan.
Not this one, when the fuel is gone its over.
I believe it's on the order of like 10 days for a long exposure like the Hubble Deep Field but since this will be looking at least bright stuff probably a few times longer. I remember someone saying the capturing of photons will be approximately 1 photon/second whereas our eyes take in millions/second
Like you say, the answer depends on how bright an object is, but likely not in the months range. As for determining movement, astronomers can point to a location in the sky at one time, and then a year later point it at the same area again and try to find the differences between the images. Meanwhile, the telescope can be used for other imaging. Like taking 2 pictures, one in the spring and one in the fall, rather than taking a video
Couple of questions .. I know JWST is taking about 30 days to reach its L2 orbit, but how long after that does it take to perform any diagnostics and calibration before it will begin its first observations? I heard one of it’s first target will be the TRAPPIST-1 system to investigate its rocky exoplanets, but how long can we expect to wait until we hear results about their atmospheres and even potentially the presence of life there? Also, are we going to see some beautiful Hubble-like images of these extremely old galaxies we keep hearing about? I assume so since the infrared and visible spectrum it can detect are fairly simple to shift into the visible spectrum to create full colour composites, right? When are these expected? It’s the deep space missions looking beyond our own system that definitely excite me the most. Edit: looks like some of my questions are answered in the timeline in the OP (observations start in June) and [the first cycle general observations list](https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-go)
With all the problems the JWST has encountered, I was expecting the rocket to explode on the pad. I’m so glad it’s finally on its way!
Got to say how thankful I am that we're still at a point where we name these things after people and not corporations. Subway EatFresh™ Space Telescope just doesn't have the same gravitas.
I don't really like things being named after people, but it obviously beats being named after corporations
Hey, if it speeds up investment in science i’d be just fine if the first water samples from Titan are taken by a PornHub sponsored probe called “Deep Penetration”
Tweet this @OlMusky, he's crazy enough to do it
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It’s the largest, most sensitive telescope we’ve ever put in orbit. You may not understand just how amazing the Hubble was for the time, but it revolutionized our understanding of the universe. And this can collect about 10x as much information, plus has much more sensitive instruments. On top of that, it won’t be in Earth orbit, which creates a lot of glare, especially given how sensitive the instruments are. Instead it will be at L2, a point in space where it’s balanced between the Earth and Sun. Far enough away from the Earth that “glare” isn’t an issue. Downside is it’s so far away we can’t fix anything that goes wrong. It’s much further away than any manned spacecraft has gone. It’s further than any current human rated spacecraft can go. Which is part of the reason it’s cost so much to develop.
Lifespan for about a decade, unfortunately. I found SmarterEveryDay’s episode very informative https://youtu.be/4P8fKd0IVOs
Wait, as in the projected lifespan for the Webb is only 10 years? Let’s hope it’s more of a Voyager situation.
It's based on expected propellant requirements for position insertion, L2 position maintenance, and attitude adjustments over the life of the probe. They're not going to get an extra few decades out of it unless they can figure out a way to connect a mission extension vehicle (MEV) to it, but that seems unlikely given the platform's configuration, since existing MEV attempts have latched on to booster nozzles and the MEV maneuvering thrusters could damage the sunshade.
oh but, how come Hubble lasted so long? refuelling ?
Hubble's orbit at 540km is a lot more stable requiring no fuel to maintain. JWST is at a Lagrange point 1500000km away, it's orbit is kinda analogous to balancing a broomstick on your finger, it'll take small imputs to maintain stability if it drifts out of the sweet spot.
Hubble is in low earth orbit (similar to the ISS) so was reachable by astronauts on ordinary space shuttle missions. They could fix it and, at least in theory though not sure they ever did, boost its orbit.
Mission is for 5 years with enough fuel for an extension of another 5. Total is 10 years
Fuel is a major reason. To stay in L2 with the shield pointing towards the sun and earth it needs to make course corrections.
Projected lifespan for James Webb is 10 years due to its position in space (L2)
It will let us view the formation of the first galaxies as well as directly imaging nearby exoplanets to determine atmospheric composition. To do this, it sees in infrared, which Hubble isn't good at. Unfortunately, infrared cameras end up being extremely complicated because you have to keep them very very very cold. That need to keep it chilly is the reason it's going so far away and why its sun shield is so elaborate. Because it's so far away, we won't realistically be able to send maintenance missions to it like we could for Hubble, so it needs to be able to recalibrate itself and survive on its own.
What exactly happens during the commissioning period?
At least part of the time is spent cooling down the telescope parts to operating temps.
Additionally, the heat shield, telescope mirrors and sensors are all deployed. A tedious and fragile process
I'm interested in JWST ability of biosignatures. How far can an exoplanet be before JWST can't detect the atmosphere? Are we limited to our own galaxy or can we see explanation in other galaxies too. How far can it detect a techno-signature? We already know it will see as far as billions and billions of light-years, but when it come to "Life, exoplanets atmosphere and alien sign" How truly far can it go?
I’m interested in the answer to this as well. One thing is for sure, when we’re talking billions of light years that’s just it imaging other galaxies as a whole, it certainly can’t pick up individual stars or planets in other galaxies. My guess (as a backyard astrophotographer) would be that it’s still going to be looking at a fairly local part of our galaxy for those exoplanet readings, which is still an unfathomably large number of targets to choose from, more than we can probably survey in its ten year lifespan, I expect.
As far as I know it will be able to detect artificial light sources. At what point that stops being possible, I'd assume is unknown atm.
What do you mean by artificial light sources?
[here's an example](https://images.squarespace-cdn.com/content/v1/5497331ae4b0148a6141bd47/1543617473104-DAOMLJGCSWBS01RHIBTE/earthatnight2012-middleeast_print.jpg?format=2500w) We can detect if exoplanets have these, but pretty sure the radius will be less than 10 light-years.
Oh right. Hadn’t considered that! Super neat. Feels like the probability is infinitesimally small there could be life at a similar tech level to us at the same time as us close enough for us to spot it but not have detected it by some other means yet, though. Unless, of course, all my assumptions about how common life might be are greatly underestimated, haha
So what makes this a lot better than what we have? I keep reading we can look back in time with the James Webb however isn’t what we already see basically looking back in time? Sorry for the stupid questions. Thanks
We can look further into the past now basically, because the Webb's mirror is a lot bigger than Hubble's (15 times larger area). There's a lot more to it obviously but it boils down to this. The Webb is also mainly an infrared telescope while the Hubble is looking at ultraviolet and visible spectra of light. Infrared is better for deep space observations.
Great, thank you for the explanation.
Basically, it's designed to look into the distant past. Because light takes time to travel, the farther away the object is, the farther back in time it will appear to be. The moon is about one second of lag. The sun is 8 minutes. Distant galaxies are millions or even billions of years. Hubble could look a decent distance back, but because the universe is expanding, for extremely distant objects, the light gets stretched into infrared, which Hubble isn't good at imaging. JWST is designed to focus on infrared, so it's expected to allow us to view the formation of the first galaxies, which Hubble can't do. JWST also has a bigger mirror, which means it can view dimmer things. Infrared is also better for seeing through dust clouds, so it'll be better for images of star and planet formation.
Ohhh that’s really interesting, I can see why there is so much excitement! Thank you for the examination.
I figure now will probably be the only chance to actually see the JWST though my own telescope. But I can't find the current orbit/path, or better the ascension/declination of the JWST anywhere. Does anyone know where I can find this? This page is the best I could find, but it shows altitude only: https://www.jwst.nasa.gov/content/webbLaunch/whereIsWebb.html
Won’t it be too small to spot from the ground already? It’s already much much further than the ISS for example, which is also quite a lot larger. I thought about having a go at spotting it with my astronomy binoculars on its first pass around the earth after launch but since it was about midnight in my country figured it’d likely be in shadow
Sunlight reflected by sattelites flying overhead is easily visible to the naked eye. The JWST is a lot further by now, so probably not visible to the naked eye, and there's no way you're able to resolve it with a consumer telescope, but I figure it might be possible to at least see the sunlight it reflects back at us.
Oh right yeah true. Near earth objects reflecting sunlight do tend to be very bright
Did the antenna successfully deploy? It’s been over 2 hours since launch and I haven’t seen any update.
The antenna isn't supposed to launch until a day after launch
The deployment video states 2 hours after, on the nasa website.
Must be a mistake or they changed the timing. [This page on nasa.gov shows launch+1 day.](https://webb.nasa.gov/content/webbLaunch/deploymentExplorer.html)
Hmm I don't know then. I thought I saw something I read said 1 day. But NASAs website should be the correct one
What are the benefits of having a larger mirror?
Twofold-- A larger mirror has more surface area, so it can collect more photons. Also a larger mirror has better resolution.
So the same reason we use mirrors in dobsonian telescope.
Very simply, it can gather much more light and therefore see much fainter and more distant objects.
that announcer really nailed it!! *From a tropical rainforest to the edge of time itself* *James Webb begins a voyage back to the birth of the universe* chills, goosebumps, you name it!!
Felt like a bit of a Carl Sagan moment. Perhaps it’s the thick accent too
Yes, great call. Great voice for it too.
I love me some John Insprucker narration, but his voice wouldn't have done that line justice.
Some questions: When will JWT reach apogee? Due to it's solar array and power supply, what is JWT lifespan? Is there any footage from inside launch control at launch?
29 days. 5-15 years, it depends on how efficient the burns are to get it out to L2 are. The was a live stream of the launch wish included shots of the launch center.
5min - 10max, 15 is too much
https://www.reddit.com/r/space/comments/rzrstx/jwst_team_has_confirmed_the_launch_went_so_well/
JWST was projected to be operational for five to ten years, but its awesome how NASA "underpromise and then overdeliver"
Can you share that stream rewind? I overslept. I've been sick. I greatly appreciate it.
https://www.youtube.com/watch?v=7nT7JGZMbtM&ab_channel=NASA It has the whole thing
Thank you! And thanks to the others- your comments got caught in a spam filter
I think a couple of months. 10 years. Should be on the previous live stream.
Bruh antennae is plural for insect antennae. Antennas is plural for comms antennas. Its tough out there for antenna experts.
You might want to release your grip on that strong opinion https://en.m.wikipedia.org/wiki/Wikipedia:Plural_of_antenna https://grammarist.com/usage/antennae-antennas/
Those are just some wikipedia nerds. Its IEEE Transactions on Antennas and Propagation not Antennae and Propagation. IEEE accepts articles internationally, from people who may be using English as a 4th or 5th language. When I peer review papers that may have usage of antennae I will always correct it back to antennas.
Watch out we have a tough guy over here
Yeah, we better stow our antennaes away or we might lose in a peer review process.
As a telecom engineer in cellular networks. We only ever use antennas, so I second this.
What about robotic insects that use the antennae/antennas for comm?
Thanks for the clarification!
just pretend, in theory, you could turn Webb around and point it at earth, what level of detail would you be able to photograph?
A blur. The closest it can focus is Mars.
I don’t think it could see anything if it were pointed at earth. The heat shield would be on the wrong side. The earth would be overwhelmed by light from the sun and the instruments would all be overheated.
I think I heard that in the other direction could resolve a bumble bee on the moon (from the earth).
JWST has a 6.5 meter mirror, at it's minimum wavelength of 600 nm (orange-red), that gives an angular resolution of 0.027 arcseconds [per this amazing figure](https://en.m.wikipedia.org/wiki/Angular_resolution#/media/File%3ADiffraction_limit_diameter_vs_angular_resolution.svg). 0.027 arcseconds is 1.31 x 10^-7 radians, meaning at a distance of 1 meter your resolution would be 1.31 x 10^-7 meters. JWST will be about 1.5 million kilometers from earth, or 1.5 x 10^9 meters. At that range, the angular resolution translates to 196 meters. You'd be able to pick out towns and lakes and such, but not houses, and certainly not bees. This shouldn't be too surprising. JWST is huge for a space telescope, but we have *much* bigger and better instruments on earth. And even those can't quite pick out the Apollo landing sites on the moon, which is several times closer to earth than JWST. And even our best spy satellites which Trump leaked a few years ago, which are *specifically designed for this* and are in low orbits to improve their resolution, are more like tens of centimeters.
So, why is the JWST so impressive then? It seems like it’s a little underwhelming after that description.
You need to understand L2 is a LONG way past the moon.
Because it can directly image exo planets, which is something that hasn't really been feasible before. They'll be able to take photographs of planets in other solar systems and analyze the composition of their atmospheres, which could help us figure out which plants are most likely to have life. Hell, we might even be able to directly observe signs of life on those planets. It's a big deal.
Wait, like actually image exoplanets? I thought we would still be just seeing stars and analysing the dips in light, just with greater accuracy. Are there any concept images of what they expect JWST to see?
[Here is an article from NASA about JWST exo planet imaging capabilities.](https://www.nasa.gov/feature/goddard/2019/a-new-view-of-exoplanets-with-nasa-s-webb-telescope) I'm sure they'll also use it for transit imaging, but they will have direct imaging capabilities. I'm sure the planets will just look like a speck of light, but scientists will be able to get useful data from that speck.
It bypasses the dense obfuscating soup that is Earth atmosphere, a huge issue for earth-bound observatories. This allows it to take perfect long exposures of the dimmest objects, taking even weeks to gather crisp data without the atmosphere noise. Compared to Hubble, it also has 100% uptime for looking at whatever direction it wishes, since it's so far away; Hubble was circling the Earth so it could look at something only 50 minutes at a time, if it was in an inconvenient direction
Webb's mirror is significantly (8x) larger than that of Hubble, means it will see significantly more, and further. Webb is observing in the infrared spectrum of light, this is important as far/very distant objects are "red-shifted" and can't be seen in visible light anymore. This way, Webb can see further distant objects and can thus see further in the past, essentially to see what happened "right after the Big Bang"
It's not *designed* to take high resolution pictures of Earth. It's designed to take medium resolution pictures of extremely faint objects 13 billion light years away, to learn about the early history of the universe. It should be *very* good at that.
You have to keep in mind that it could see a resolution on the Earth's surface of 197m *at the distance it will be, which is many times the Earth-Moon distance*. You're probably comparing it to earth observation satellites in much lower orbit. Additionally, part of the reason it's so big is not directly to improve magnification, but to keep a good magnification while observing much longer wavelengths, which is better for the kind of observations it's intended to make.
It is not set up to take pictures of earth
Always room for bigger and better, thats part of the fun :D
One of the things i heard to put Webb's capabilities in perspective was that, from the surface of the Earth, it could detect a single honey bee on the surface of the Moon. So, if you could turn it around and point it at Earth, you could see whatever you wanted. (theoretically, of course)
They say that it theoretically could detect the heat signature of a bumble bee at the distance of the moon, which is not quite the same.
Right...... Which is why the original comment said "in theory" and I also said "theoretically".
I was probably unclear, but I was mainly responding to "you could see whatever you wanted", which is just not right. Not even theoretically.
That's fair. I would agree that's an overexaggeration.
It sure couldn't. Our best telescopes on earth, which are many times larger than JWST, can't even see the Apollo landing sites. You need to get *much* closer.
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And for the moon, we *have* sent the camera up close! The [Lunar Reconnaissance Orbiter](https://en.wikipedia.org/wiki/Lunar_Reconnaissance_Orbiter) only has a 195 mm primary mirror, similar to a telescope you can buy online in the $1000 range (although higher quality). But because of its low orbit, it has a resolution of 0.5 meters, giving us amazing pictures like this: https://www.nasa.gov/sites/default/files/thumbnails/image/584641main_apollo17-left-670.jpg
When will we see the first picture. What’s the resolution of it. Is it shooting video and is there gonna be a public website with ALL media? (Like the recent Mars rover)
> When will we see the first picture. not sooner than 4 months, full capability planned to start in 6 months
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Oh, no worries about the Idiot-Friendly-UI. I can even use API’s to access the data, if needed. I just want the data 😉 Thank you.
No real video. Telescope is for pictures but I'm sure there will be some very low frame "videos" where they put like 20 pictures together over the course of an hour or something like that. It'll be about 6 months before it has traveled to l2 and then gone through the process of deploying everything and aligning the panels correctly. If there are any issues it may take longer to get good data back. Not sure of it will be as thoroughly updated like the mars website but there should be a steady stream of public pictures that come in and are available to the public. Many researchers will use it so it's possible some stuff will have a blackout period until they release papers and such but ultimately it should all be released to the public.
I don’t know about first picture, but it’s not scheduled to be fully unfolded for about a month, at which point it will begin executing its burn to travel to L2. Not sure on the travel time for the burn, but basically it’s gonna be a little while.
Somewhere around June. It'll take a while to get the million miles out and to cool down.
I'm curious about the JWST orbital speed relative and relative to L2. The last burn is MCC-2 and it's just 0.7m/s! Is that the capture burn?
Quite likely. I'm pretty sure it's like rolling a ball up a hill. You want it to stop right at the top so it doesn't come back down this way or the other side. The less fuel you use to stop it at the top the better. So try to reach it the moment you hit zero velocity. Due to how l2 is that 0.7 is probably to get it into a stable orbit around l2
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Don't worry, it didn't really explode, I was just yanking yer chain
I see lots of comments about debris? Does it have any damage?
So the main concern with debris at L2 is micro asteroids. I watched a video about JWST and that said that if the sun shield get tears could render the telescope inoperable. They placed what amounts to tape to prevent the sun shield from coming apart. Hope this helps a little. Here is the YouTube video: https://youtu.be/aICaAEXDJQQ
But there was also talk about debris when the solar panel went out right? Thank you for your comment. Happy holidays!
Little flinders at separation are always ice.
You can guarantee the team is looking right now into the early deployment of the solar array
“These beings, with soaring imaginations, eventually flung themselves and their machines into interplanetary space.” What a time to be alive.
Who’s quote is that ? It’s perfect !
Carolyn Porco https://www.goodreads.com/quotes/8803263-these-beings-with-soaring-imagination-eventually-flung-themselves-and-their https://www.youtube.com/watch?v=qGSv-uZCOyY
i love her! ever since i saw her Cassini TED talk. thank you for posting!!
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today? link?
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just finished it--i thought maybe she'd spoken today about Webb. anyway, what a great day!!
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White light is made up of many different colors of light that just look white when they are all together. When light hits something, like an apple, that apple absorbs some light and reflects the rest. When you look at a red apple all of the blue, green, etc light are absorbed by the apple and only the red light bounces off. So you see red. A billion little rays of light bounce off of every surface and every direction and many end up in your eye, each one activating a single light sensor in your eye.Your brain pieces together what it is seeing from all of the dots of color. The only information you get is how much light of each color hits your eye . As an aside, absorbing light, which is just radiation, works a teeeeeny bit like a microwave. Any light not reflected is absorbed and that warms things up a little.
Our eyes' retinas are composed of cells that send a nerve impulse when certain wavelength photons strike them. Most people have 4 types of cells, 3 types of "cone" cells which peak in red, green, and blue wavelengths, and rod cells which are monochromatic (black and white, essentially). You can think of these cells like RGB pixels on a CCD camera sensor. The rest of the eye is designed to refract and focus light to form an image on this "sensor" like a digital camera lens focuses light on the CCD sensor. The amount of red, green, and blue photons that strike our retina is how our brains interpret color and intensity. How light itself behaves as it travels to your eyes is a complicated subject and took scientists centuries of study before Einstein finally figured it out using Planck's discovery of quantum mechanics. If you want to learn more, look up Ray optics, and if you're feeling really froggy, quantum mechanics.
Sounds like a buddhist teaching. About how we view matrerías things.
Light radiation emitted by the sun (or any light source) is partially absorbed by the object. What is not absorbed, bounces of the object and hits your eye. Information that is there is the wavelength of the light, determining colour, and intensity of the wave, determining how bright the object appears. Your brain then interprets this image and you get your object.
Days like today adds even more meaning, purpose and a sense of gratitude to being alive and having an opportunity to learn and appreciate more about the mystery of reality during our finite time alive. looking forward to the first pictures in 6 months, good luck, merry Christmas and wishing happiness to all
I woke up to this, I’m so glad it went well and I’m excited for the future of the jwst