The Sky at Night - Webb Telescope: The Story So Far
The Sky at Night - Webb Telescope: The Story So Far
Transcript
00:00In July 2022, the first images from the James Webb Space Telescope were released, to the
00:12joy of myself and millions of astronomy fans all around the world.
00:27At the time, we were all blown away by the stunning new images. Their exquisite detail
00:32reminded us of the beauty of the universe in which we live.
00:36But as well as the pretty pictures, we've also been getting data from the telescope's
00:40various instruments, which have continued working throughout, flooding scientists with
00:45information about planets, galaxies and so much more besides.
00:50Now we're two years on, and in that time, scientists have been busy analysing the data
00:55and putting out papers. But has JWST been as exciting and groundbreaking as we'd hoped?
01:01And has it been plain sailing for the telescope itself? Well tonight, we're looking at the
01:05story so far of the James Webb Space Telescope. Welcome to A Sky At Night.
01:25So today, I'm on the road, retracing the steps of a journey that Chris made in the
01:46summer of 2022, when we got the first release of the data from the James Webb Space Telescope.
01:54Chris had hit the road to meet up with researchers around the country to find out what they were
02:00hoping this new space telescope could reveal.
02:03Since then, these scientists and others have been working hard to understand the information
02:11that the JWST sent back, and we're off to find out what they've discovered.
02:19But first, what has the JWST story been so far?
02:24Billions of years ago, when the universe was young, the first galaxies began to shine brightly,
02:30illuminated by some of the earliest stars. Their light has been travelling through the
02:34cosmos ever since, streaming unnoticed past the Earth for all of human history. Unnoticed,
02:41that is, until two years ago, when that ancient light encountered a fragile golden mirror
02:47floating in space a million miles from here. It was brought to a focus in some of the most
02:51delicate and sophisticated instruments ever launched, and we can read its story for the
02:56first time. This is the miracle of JWST, a telescope built to show us the hidden places
03:03of the universe and reveal unimagined wonders. In the more than two years since it launched,
03:08the telescope has had its problems, sure. It's been hit more than 20 times by micrometeorites,
03:14tiny particles of dust zipping about the solar system, and one of them has left a permanent
03:19dent on one of those mirrors. JWST's controllers now avoid pointing in directions where there
03:25are plenty of micrometeorites, keeping the telescope safe. Actually, we've learnt about
03:30the distribution of dust in the solar system, a scientific reward for placing our telescope
03:35in such peril. Otherwise, despite occasional problems getting used to using JWST's instruments,
03:42our biggest problem has been deciding where to point. Astronomers around the world have
03:47produced enough ideas to keep seven or eight versions of JWST busy, and though it's easy
03:52to get lost in the iconic images, all of the horsehead, Orion, merging galaxies, the telescope
03:59actually spends about three quarters of its time doing spectroscopy, splitting up the
04:04light it receives into its constituent wavelengths, revealing what planetary atmospheres are made
04:09of, what's happening deep in the heart of star-forming regions, and finding out quite
04:14how far away those oh-so-distant galaxies are. Answer? Very. Together, JWST's three
04:22instruments have shown us a completely new view of Mars. They've revealed rings around
04:26a centaur asteroid in the frozen outer solar system, have given us a new view of old clusters
04:32of stars in our galaxy, and shown us spectacular star formation in more distant systems. Best
04:39of all, it gives us new views of very familiar objects, like this one of the Ring Nebula,
04:44which shows mysterious spikes pointing away from the centre, a ring that's comprised of
04:4820,000 separate clumps of gas, each the mass of the Earth. And the telescope has also revealed
04:55a complex soup of carbon molecules, unusual for a planetary nebula. And this is just one
05:01object. Imagine how much more there is to see. The truth is, we could fill every episode
05:07of the sky at night for the next 20 years with new data and new images from this most
05:11marvellous of observatories. And you know, we probably will.
05:23So that's what the JWST has achieved. But science can be more complicated than that.
05:29For every answer, it reveals another exciting question.
05:34I'm off to the University of Bristol to find out what Dr Hannah Wakeford has discovered
05:41since she met Chris two years ago. Hannah, good to see you again. Good to see you.
05:47Can you believe it was two years since you last met up with Chris? Not really, to be honest.
05:53It seems like yesterday we were just getting data down from the telescope.
05:57Well, I wanted to play you the clip just to remind you what happened.
06:00So you've been planning these observations with colleagues for a long while, I know.
06:05How does it feel to finally have data sitting on this computer?
06:08Overwhelming. I'm getting all teary. Every time I think about it, I'm just like,
06:12this is so amazing. You were truly so excited to get the data.
06:17I'm still so excited to get the data. Whenever I can get data, I'm happy to get data.
06:21I think that's the beauty of being an observer, is just we're always excited to learn new things.
06:27One planet that Hannah and her team were excited to observe with JWST was WASP-17b.
06:36And what's interesting about this exoplanet?
06:38So it is a giant planet. It is about twice the radius of Jupiter, but only half of its mass.
06:44So it's very low density.
06:46So this is an artist's impression that is now based on the observations we got with JWST.
06:51Oh, wow. So people take that data and then create what they think it might look like.
06:56So we talk with the artists and we work with them to try and describe what we're seeing.
07:01Now, the data itself looks something like this.
07:04Less artistic.
07:06It's a little bit harder to sell, let's say.
07:09Data from the Hubble Space Telescope had already revealed tiny particles in the planet's atmosphere.
07:16But Hannah had hoped data from JWST's mid-infrared instrument
07:21could finally tell them what these particles were made of.
07:25With JWST, it's our only opportunity to get these features way out in the infrared
07:31which tell us what that cloud is actually composed of.
07:35And in this case, our silicon dioxide.
07:37So if there were not these clouds made of silicon dioxide in the atmosphere,
07:43we would have measured this yellow line.
07:46OK.
07:47The peak on the grey and pink lines compared to the yellow one
07:51show that light from WASP-17b's local star
07:54had been absorbed by a specific molecule in the atmosphere.
07:59Hannah was expecting it to be magnesium silicates,
08:03particles which make up rocks and sand, as seen on other exoplanets.
08:07But that's not what they found.
08:11So what we actually found was more of that kind of pure quartz form.
08:15And this is what quartz looks like here on the Earth.
08:17So it's a solid, it's kind of nice and glittery and it's clear.
08:21When you've got magnesium silicates or iron silicates in this case,
08:24you get more of that amethyst colour.
08:26Yeah, so it's like that's a contamination.
08:28Exactly.
08:29But it leads to that beautiful colour.
08:30What we actually think is happening is we've got these beautiful quartz crystals
08:33that are being formed high in the atmosphere.
08:35And then what we found was that these are nanocrystals.
08:39They're very, very tiny particles,
08:40about 100 times smaller than the width of a human hair.
08:43And that's what's really interesting,
08:45is that tells us that these are likely the precursors,
08:48the first things that are forming in the atmosphere.
08:52This discovery, along with data from hundreds of other exoplanets
08:56that JWST has now studied,
08:58is revealing some of the very fundamentals of our universe.
09:03These planets operate as these individual little laboratories for us.
09:07Oh, yes.
09:08Because we can't create these conditions on Earth.
09:11This is a high-temperature, low-pressure, hydrogen-dominated environment.
09:17Oh, sounds flammable.
09:19It's not fundable.
09:22It allows us to really take these natural test tubes
09:26to try and understand what's going on.
09:28How would this kind of material change under different conditions?
09:32And we've got hundreds of exoplanets to look at
09:35to be able to see, if we change the conditions,
09:38what happens to our clouds.
09:39Wow.
09:40So, yes, it's remote laboratories where you can do these experiments
09:43and yet you get the data and can compare.
09:45That's powerful.
09:46And that is the beauty of the thousands of exoplanets,
09:49is that we've got enough of them to start to really understand
09:52the nature of chemistry and physics that we think we understand here.
09:55Anna, thank you so much.
09:57It's been fantastic, as always.
09:59And look forward to coming back soon.
10:01Take care.
10:03I would never have envisaged
10:05that these otherworldly atmospheres would reveal so much
10:08when I worked on the James Webb Space Telescope over ten years ago.
10:12And these atmospheres are revealing detail that is unexpected.
10:16Crystalline structures.
10:18But we're detecting this from an atmosphere
10:20that is over 1,000 light-years away from us.
10:23This is the stuff that is truly mind-boggling.
10:27While Hannah has been looking at the planets around distant stars,
10:31it's the planets around our own star
10:34that two years ago led me to the University of Leicester
10:37just after some astonishing pictures were hot off the press.
10:43Just a few days ago, this image of Jupiter was released.
10:46And what I love about this image
10:48is that it shows an old friend in a new light,
10:51with Jupiter's belts and the great red spot glowing in infrared light.
10:55Since then, JWST has taken a closer look at all four outer planets.
11:00Four outer planets in our solar system.
11:03And George is off to find out what they've revealed.
11:07As an exoplaneteer, I usually spend my time
11:10studying planets orbiting distant stars,
11:12so it's kind of nice for a change of pace
11:14to learn about what's going on with the planets in our own solar system.
11:22I'm meeting Professor Lee Fletcher
11:24to find out how the last two years have been for him.
11:28Welcome to Leicester. Thank you so much. It's so good to be here.
11:31First of all, I just want to remind you of what you said last time.
11:34OK, right. We were here.
11:36So tell us about the other planets. What will we see?
11:39Uranus is coming up in August and September.
11:42Saturn is coming up in October.
11:44And Neptune, we're going to have an opportunity to do that in 2023,
11:48so about 12 months.
11:50It is a tremendously exciting time,
11:52and it's going to keep us with sleepless nights
11:56and heavy workloads, I think, for at least five or six years.
12:02You said sleepless nights and heavy workloads.
12:05Has that become a reality?
12:07Gosh, that feels like a lifetime ago as well.
12:09It's been a couple of years now since we filmed that,
12:12and honestly, all of our dreams came true.
12:14We got all of the data sets that we were planning when Chris and I spoke,
12:18and the data sets have confounded us, confused us, got us excited.
12:23We're going to start with Jupiter.
12:25So I hear you've had a few surprises, pleasant ones, though.
12:28Yeah, I think if you think about the Jovian system,
12:31you might ask the question quite reasonably.
12:33We've been there before. We've sent missions there.
12:35What else can JWST really tell you?
12:37And even I was surprised when we got some of these data back.
12:40So on the screen behind me is one of JWST's fantastic images of Jupiter,
12:45and what we can do is when you look at Jupiter over several hours,
12:48you can see all the cloud features moving around.
12:50We did it at a different wavelength of light,
12:53one that you can only really access with JWST,
12:56and lo and behold, out pops a brand-new jet stream
12:59that's gone hidden from Earth view
13:01for the last four decades of observations of this planet,
13:05and it was just there waiting for us in the data.
13:07So my colleagues published this last year,
13:09and what this is is a very powerful stream of air
13:12high above the Jovian equator
13:14that is somehow linked to the atmosphere high above,
13:17and this is something that was completely unexpected
13:20when we first started inspecting these data.
13:22It seems we've learned a lot about Jupiter's system.
13:25Have we learned anything new and exciting about Saturn so far?
13:28On the screen behind you is the first image we captured of Saturn.
13:32The atmosphere looks fairly bland there,
13:34but the rings are absolutely resplendent in these data.
13:37We saw that the rings are astonishingly pure crystalline water ice
13:42with just a tiny, tiny fraction of things like organics
13:45peppering the rings to give them their glorious colours.
13:48We saw that the atmosphere of Saturn, which is seasonal,
13:51and we had a prediction that the atmospheric flows on Saturn
13:56would shift direction,
13:58and those predictions were borne out quite accurately.
14:02While Jupiter and Saturn are building
14:04a more detailed picture of their systems,
14:07it is the two most distant planets
14:09that have Lee and his colleagues relooking at their models.
14:12So now what about our two big enigmas, Uranus and Neptune?
14:17So you have to remember that Uranus and Neptune
14:19have only had a single flyby mission,
14:21the venerable Voyager 2 back in the late 1980s,
14:24and since then we've been observing with ground-based telescopes,
14:27with the Hubble Space Telescope,
14:29and we thought we were starting to generate
14:31a decent understanding of these worlds.
14:33And unfortunately, when we started to apply our models,
14:38based on all that prior knowledge, to the new JWST data,
14:41we started to realise something wasn't adding up.
14:44Something was missing.
14:45It was like making a cake
14:47and having all of the ingredients for the cake,
14:49but then when you actually taste the cake,
14:51there's something just not quite right in the flavour,
14:53and it's that missing ingredient in our spectral models
14:56that we're trying to pin down at the moment.
14:58But that's exciting, right,
15:00because it means that we are going to learn something fundamentally new
15:03about the chemical composition of these two worlds
15:06that we didn't expect to be even asking about
15:08when we first launched JWST.
15:12Research continues on Uranus and Neptune,
15:15this was to be expected.
15:17Lee did say there was about six years' work to be done
15:20and we've come back after just two.
15:22But it still amazes me just how much JWST
15:25is changing our understanding of objects around our own sun.
15:30The solar system is our home planetary system
15:33and we've been studying it with telescopes for a while now
15:36and, you know, staring at it for thousands of years.
15:39Is it surprising that there's still so much more new stuff to learn about it?
15:44I think whenever you have a brand new capability like JWST,
15:48there's always going to be something, some wavelength of light
15:51that's going to deliver something that surprises you.
15:53And you're absolutely right,
15:55the solar system has been fabulously well studied,
15:57but some of the questions that we're trying to answer now,
16:00like little pieces of a jigsaw puzzle,
16:02they add up to a much greater, much more impactful
16:06and deep understanding of this wonderful solar system
16:09that we're a part of.
16:11Well, thank you so much for having me.
16:13It's been so great chatting to you.
16:15Always a pleasure to have you.
16:16Well, look forward to next time.
16:17OK, take care. Bye-bye.
16:21While Maggie and George have been catching up with scientists
16:24we met two years ago,
16:26I've headed to the University of Cambridge's
16:28Kavli Institute of Cosmology,
16:30where a fetching set of one-to-one scale replicas
16:34of JWST's mirrors can be found.
16:38Because light can travel through the universe
16:40for millions or even billions of years,
16:43our telescopes are time machines,
16:45showing us the past.
16:48And with its 6.5-metre mirror,
16:50JWST is allowing us to peer back further
16:53than we ever have before.
16:58I'm meeting Dr Sandro Tekela,
17:00who studies these very young galaxies,
17:03to find out what has been revealed.
17:05Hey, how are you?
17:06Hi, Chris, good to see you.
17:07Nice to see you. Thanks for having us.
17:09Yeah, well, welcome.
17:10Well, I'm excited by this.
17:11What did we know about the early universe before JWST?
17:15What have we learnt from all of those years
17:17of pointing at these things with the Hubble Space Telescope?
17:20Yes, so Hubble gave us really already a very good overview
17:22of what happened in the universe through most of cosmic time,
17:25which means that we are, you know, looking at the universe
17:27of the age of about two to three billion years.
17:29That's pretty good.
17:30That's pretty good, indeed.
17:31But the growth at earlier cosmic times,
17:33so that's in the first billion years,
17:35is actually the most active growth
17:36and the most interesting growth in that sense,
17:38because that's where the very first stars,
17:40the very first black holes and the very first galaxies
17:42started to form and to assemble.
17:46And it's this early universe,
17:48when galaxies and stars were first forming,
17:51that JWST is showing us for the first time.
17:56Scientists around the world are working together
17:59to build a detailed map of the deep cosmos
18:02as part of a project called JADES,
18:04the JWST Advanced Deep Extragalactic Survey.
18:10Well, I think what we should do is take a tour of some of the data,
18:13so you've got an interactive tour, right?
18:15Yes, what you see here is a mosaic.
18:17So, these are basically over, you know, 400 images
18:20that we have taken over the last two years
18:22with the James Webb Space Telescope,
18:24and we have put them together.
18:25You know, one of the very interesting structures
18:27is what we term the cosmic rose, OK, and you might see why.
18:30So, when I zoom in here, you can see that this looks like,
18:33you know, a rose-like structure,
18:35and so this system is actually very distant,
18:37formed about two billion years after the Big Bang,
18:40and what you see here is not just a single galaxy,
18:42but actually a whole group of galaxies.
18:45But JWST has been able to look back at even younger galaxies.
18:50So, are there other places we should visit in this image?
18:53So, this is one of the deeper patches in the image,
18:56and what I show you here is a galaxy,
18:59which seems to be kind of this yellowish colour,
19:01and this is basically the most distant galaxy that is known to us.
19:04That's splodge. Yeah, that's splodge here.
19:07So, it's really probing, basically,
19:09the earliest structures we know in the universe.
19:12This is the furthest back in time we've ever seen,
19:15showing us the very earliest moments of our universe's story,
19:19fewer than 300 million years after the Big Bang.
19:23So, when you look at this image,
19:25there are lots of splodges all over the place.
19:28What made you look at that one in particular?
19:30We have been seeing this object already in the very early data
19:33we obtained nearly two years ago,
19:35and I think the surprising thing was that it's actually very bright.
19:38And so our initial reaction was that, well, it cannot be that distant
19:42because it's too bright.
19:44And so we took better data, and in particular we also took spectroscopy.
19:48We could clearly see that, no, that galaxy,
19:50that this yellow blob here,
19:52is really this most distant galaxy that we have ever seen.
19:56So, if this is the record holder, how common are galaxies like this?
20:00Yes. So, we don't know at the moment.
20:03It's really...
20:05It's basically far off in whatever we have seen before.
20:08And so, in that sense, this galaxy is very peculiar.
20:10It's really bright. It's very early cosmic times.
20:13And so it's a really one-off record holder at the moment.
20:16But it might be that because we have been biased
20:18in the way of how we thought about these early galaxies,
20:21we were looking mostly for very, you know, young systems,
20:24quite small systems.
20:26We might have seen those galaxies, but we said, like, oh, no.
20:29So, we have to go back and look more carefully at those systems.
20:32So, maybe they are more common than we thought.
20:35Finding this particular galaxy may have been a surprise,
20:39but it's just one of many that JWST is detecting
20:42from the very early universe.
20:45And the picture the telescope is giving us is of a young universe
20:49full of galaxies growing quicker
20:51and forming stars faster than had been expected.
20:57How much has this early universe surprised you,
21:00compared to what you thought you were going to get a couple of years ago?
21:03It was really surprising in the sense of how much excitement
21:08it triggered, also in the general public.
21:10So, I think, you know, it was beyond just, like, you know,
21:13me looking at the screen and being astonished by these beautiful images.
21:16For me, personally, I think I was surprised to see
21:20of how much, how good the telescope works.
21:23It really works amazingly well and, you know, like,
21:26the images are beautiful, but we can take spectra
21:29and really learn about these, you know, systems in really great detail
21:32that I didn't expect to, you know, only maybe dream about.
21:35Well, thank you very much. It's fascinating stuff.
21:38Thank you very much, Chris.
21:40While the scientists we've been meeting this month
21:43have their heads down working on the data that JWST is supplying,
21:47Chris is in Bedford, looking up to the skies.
21:53The pictures taken by JWST over the last couple of years
21:57have been nothing short of mind-blowing.
21:59And although we can't get the same level of detail
22:02a million miles away here on Earth,
22:04we can find the objects in those iconic JWST images.
22:11While what we can get from our back gardens may not compare,
22:15the objects are slowly moving out of the sun's glare
22:18and will become spectacular at the end of this month.
22:22In particular, an early morning view
22:25low over the east-north-east horizon before sunrise
22:29will reveal bright Jupiter,
22:31brightening Mars
22:33and binocular dim Uranus
22:35against the wonderful stars of Taurus.
22:38At the end of July,
22:40the waning crescent moon moves through this region too,
22:44creating a lovely scene just asking to be photographed.
22:52Saturn is further to the west of this group,
22:55with dim Neptune in tow just to the east of it.
22:59Saturn will be reaching its highest position in the sky
23:03due south under relatively dark conditions during August,
23:07this being the best time to get a steady view of the planet.
23:12One of the most popular images taken by the Hubble Space Telescope
23:16was that of the Pillars of Creation.
23:19JWST took that iconic image to another level.
23:24While you may not be able to see the pillars themselves
23:27unless you have a large telescope,
23:29you can see the nebula in which they're located.
23:32That's the Eagle Nebula.
23:34Now, this is best seen in the summer months
23:37when it's at its highest position above the southern horizon
23:40under dark conditions.
23:42The Eagle Nebula can be found by first identifying Altair,
23:47the southernmost star in the summer triangle asterism.
23:51This is the brightest star in Aquila the Eagle.
23:55Locate Delta Aquilae in the centre below and right of Altair.
24:00Extend the line from Altair through Delta
24:03for three times that distance again,
24:06passing through the diamond-shaped constellation
24:09of Scutum the Shield as you go,
24:12after which you will find the Eagle Nebula, known as M16.
24:18Through small and medium-sized telescopes,
24:21the Eagle Nebula appears as a cluster of stars,
24:24the faint nebula gas being hard to see.
24:28Long exposure photography or a large scope
24:31are needed to reveal it properly.
24:34While you're in the region,
24:36look slightly south of the Eagle Nebula
24:39to see the Swan Nebula, M17.
24:42This is much easier to see.
24:45It's wonderful to think that with amateur telescopes
24:48or even just your eyes,
24:50you can see the same objects
24:52as the most powerful telescope sent into space.
24:55Sure, we can't see the same level of detail,
24:58but it's nice to be reminded that as we send telescopes
25:02deeper and deeper into space,
25:04we're all looking at the same universe.
25:07As ever, if you get some images,
25:09do share them on the Sky At Night Flickr,
25:12and we'll pick some of our favourites and show them next month.
25:16Further details can be found at bbc.co.uk forward slash sky at night.
25:21In the meantime, here are some of our favourites from last month.
25:32MUSIC
25:51JWST can do so much with a single image.
25:54It can astound, amaze and surprise us.
25:57And so we thought before we go,
25:59we'd show you a few of our favourite images.
26:02This is mine.
26:04It's the Cigar Galaxy, M82.
26:06What you can see is a powerful wind sweeping away from the galaxy,
26:10driven by the star formation that's happening at the galaxy's heart.
26:15This is my favourite JWST image.
26:17It shows you the Goods North region.
26:19It has been imaged with JWST in nine different filters,
26:22and what you can see here are about 50,000 different galaxies.
26:26But there is one particular galaxy that is highlighted.
26:28This is GNC 11.
26:30This is the most distant galaxy with a known black hole.
26:33So this is my favourite JWST picture.
26:37It is actually a spectrum which includes the JWST information
26:43from the clouds in the atmosphere of WASP-17b,
26:47and the information that we had previously from the Hubble Space Telescope.
26:52So this is my favourite JWST image,
26:56and it is, believe it or not, the Horsehead Nebula.
26:59It's looking over the very top of the horse's head,
27:03which has been an object very iconic to me
27:06as I've been growing up with astronomy.
27:08So this image is blowing my mind
27:10because as JWST is looking over the top of the horse's head
27:13into deep space, what can it see?
27:15Galaxies.
27:17It's an incredible image.
27:19This is my favourite picture.
27:21This is an image of HIP 65426b.
27:24Actual images of exoplanets are a rarity
27:27because direct imaging is so hard.
27:29But this was JWST's first attempt at direct imaging,
27:32and we got this stunning picture in four different colours,
27:35which is marvellous.
27:37So I think my favourite image from JWST so far
27:40has been this image of the ice giant Uranus.
27:43I was so looking forward to seeing what Uranus and Neptune
27:46would look like through this fabulous new facility.
27:48So when these images came out, I almost had tears in my eyes.
27:51This is a destination that humanity now needs to send
27:55its next robotic explorer to,
27:57and here James Webb has captured it in all of its glory.
28:00One of my favourite pictures taken by Webb so far is this one,
28:03and it's because of a few different aspects.
28:06Firstly, I love the beautiful images, but this is raw data.
28:10Secondly, it was taken by NIRSPEC,
28:12which is one of the instruments that I worked on.
28:14And thirdly, this is showing one of the earliest galaxies
28:17that ever existed in the universe.
28:19The fact that we can build an instrument that goes up in space
28:22and tells us this level of detail is still quite mind-boggling to me.
28:27If this is what JWST has achieved in just two years,
28:30its potential over the next 10 or even 20 must be enormous.
28:35I can't wait to find out what it's going to tell us.
28:38In the meantime, we're filming our annual Question Time show
28:41in a few months, so if you have a question for this year's expert panel,
28:45go to our website right now to find out how to submit it.
28:48Until next time, good night.
29:15NASA Jet Propulsion Laboratory, California Institute of Technology