Original subtitles

In July 2022, the first images

from the James Webb Space Telescope were released,

to the joy of myself and millions of astronomy fans

all around the world.

Oh, my gosh!

CROWD EXCLAIMS

Wow, look at that.

At the time, we were all blown away

by the stunning new images.

Their exquisite detail reminded us of the beauty of the universe

in which we live.

But as well as the pretty pictures,

we've also been getting data from the telescope's

various instruments, which have continued working throughout,

flooding scientists with information about planets, galaxies,

and so much more besides.

Now we're two years on - and in that time,

scientists have been busy analysing the data and putting out papers.

But has JWST been as exciting and ground-breaking as we'd hoped?

And has it been plain sailing for the telescope itself?

Well, tonight, we're looking at the story so far of

the James Webb Space Telescope.

Welcome to The Sky At Night.

So today, I'm on the road, retracing the steps of

a journey that Chris made in the summer of 2022,

when we got the first release

of the data from the James Webb Space Telescope.

Chris had hit the road to meet up with researchers

around the country to find out what they were hoping

this new space telescope could reveal.

Since then, these scientists and others have been working hard

to understand the information that the JWST sent back.

And we're off to find out what they've discovered.

But first, what has the JWST story been so far?

Billions of years ago, when the universe was young,

the first galaxies began to shine brightly,

illuminated by some of the earliest stars.

Their light has been travelling through the cosmos ever since,

streaming unnoticed past the Earth for all of human history.

Unnoticed, that is, until two years ago,

when that ancient light encountered a fragile golden mirror floating

in space a million miles from here,

It was brought to a focus in some of the most delicate

and sophisticated instruments ever launched -

and we can read its story for the first time.

This is the miracle of JWST -

a telescope built to show us the hidden places of the universe

and reveal unimagined wonders.

In the more than two years since it launched,

the telescope has had its problems, sure.

It's been hit more than 20 times by micrometeorites -

tiny particles of dust zipping about the solar system.

And one of them's left a permanent dent on one of those mirrors.

JWST's controllers now avoid pointing in directions where

there are plenty of micrometeorites,

keeping the telescope safe.

Actually, we've learned about the distribution of dust

in the solar system - a scientific reward for placing

our telescope in such peril.

Otherwise, despite occasional problems getting used

to using JWST's instruments,

our biggest problem has been deciding where to point.

Astronomers around the world have produced enough ideas

to keep seven or eight versions of JWST busy.

And though it's easy to get lost in the iconic images...

Oh, look, the Horsehead!

Orion! Merging galaxies!

..the telescope actually spends about three quarters of its time

doing spectroscopy,

splitting up the light it receives into its constituent wavelengths,

revealing what planetary atmospheres are made of,

what's happening deep in the heart of star-forming regions,

and finding out quite how far away those oh-so-distant galaxies are.

Answer - very.

Together, JWST's three instruments have shown us

a completely new view of Mars.

They've revealed rings around a centaur asteroid in

the frozen outer solar system,

have given us a new view of old clusters of stars in our galaxy,

and shown a spectacular star formation in more distant systems.

Best of all, it gives us new views of very familiar objects,

like this one of the Ring Nebula,

which shows mysterious spikes pointing away from the centre,

a ring that's comprised of 20,000 separate clumps of gas,

each the mass of the Earth.

And the telescope has also revealed a complex soup of carbon molecules -

unusual for a planetary nebula.

And this is just one object.

Imagine how much more there is to see.

The truth is, we could fill every episode of The Sky At Night

for the next 20 years with new data

and new images from this most marvellous of observatories.

And, you know, we probably will.

So, that's what the JWST has achieved.

But science can be more complicated than that.

For every answer, it reveals another exciting question.

I'm off to the University of Bristol

to find out what Dr Hannah Wakeford has discovered since

she met Chris two years ago.

Hannah, good to see you again.

Good to see you.

So, can you believe it was two years since you last met up with Chris?

Not really, to be honest. THEY CHUCKLE

It seems like yesterday we were just getting data down

from the telescope.

Well, I wanted to play you the clip just to remind you what happened.

So, you've been planning these observations with colleagues

for a long while, I know.

How does it feel to finally have data sitting on this computer?

Overwhelming.

I'm getting all teary - every time I think about it,

I'm just like, "This is so amazing!"

You were truly so excited to get the data.

I'm still so excited to get the data!

Whenever I can get data, I'm happy to get data.

I think that's the beauty of being an observer - is just

we're always excited to learn new things.

One planet that Hannah and her team were excited to observe

with JWST was WASP-17b.

And what's interesting about this exoplanet?

So, it is a giant planet.

It is about twice the radius of Jupiter,

but only half of its mass.

So, it's very low density.

So, this is an artist's impression that is now based on

the observations we got with JWST.

Oh, wow. So...

So, people take that data,

and then create what they think it might look like?

So, we talk with the artists, and we work with them to try

and describe what we're seeing.

Now, the data itself looks something like this.

Ah, yeah - less artistic.

It's a little bit harder to sell, let's say.

Data from the Hubble Space Telescope had already revealed

tiny particles in the planet's atmosphere.

But Hannah had hoped data from JWST's mid-infrared instrument

could finally tell them what these particles were made of.

With JWST, it's our only opportunity to get these features

way out in the infrared

which tell us what that cloud is actually composed of...

Yes. ..and in this case, are silicon dioxide.

OK. So, if there were not these clouds made of silicon dioxide

in the atmosphere, we would have measured this yellow line.

OK.

The peak on the grey and pink lines,

compared to the yellow one,

show that light from WASP-17b's local star had been absorbed

by a specific molecule in the atmosphere.

Hannah was expecting it to be magnesium silicate -

particles which make up rocks and sand -

as seen on other exoplanets.

But that's not what they found.

So, what we actually found

was more of that kind of pure quartz form.

And this is what quartz looks like here on the Earth.

So, it's a solid, it's kind of nice and glittery, and it's clear.

When you've got magnesium silicates -

or iron silicates, in this case -

you get more of that amethyst colour.

Yeah, so it's, like, that's a contamination... Exactly.

..but it leads to that beautiful colour.

What we actually think is happening

is we've got these beautiful quartz crystals

that are being formed high in the atmosphere.

And then, what we found was that these are nanocrystals.

So, they're very, very tiny particles,

about 100 times smaller than the width of a human hair.

And that's what's really interesting, is that tells us

that these are likely the precursors, the first things

that are forming in the atmosphere.

This discovery, along with data from hundreds of other exoplanets

that JWST has now studied,

is revealing some of the very fundamentals of our universe.

These planets operate as these individual little

laboratories for us. Oh, yes.

Because we can't create these conditions on Earth.

This is a high-temperature, low-pressure,

hydrogen-dominated environment.

Ooh - sounds flammable.

It's not fundable, for certain. Yes!

It allows us to really take these, you know, natural test tubes

to try and understand what's going on.

How would this kind of material change under different conditions?

And we've got hundreds of exoplanets to look at,

to be able to see, if we change those conditions,

what happens to our clouds? I see - wow.

So, yeah, it's remote laboratories where you can do these experiments,

and you get the data and can compare. That's powerful.

And that is the beauty of the thousands of exoplanets,

is that we've got enough of them to start to really understand

the nature of chemistry and physics that we think we understand here.

Hannah, thank you so much.

It's been fantastic, as always,

and I look forward to coming back soon. Take care.

I would never have envisaged that these other-worldly atmospheres

would reveal so much, when I worked on the James Webb Space Telescope

over ten years ago.

And these atmospheres are revealing detail that is unexpected -

crystalline structures.

But we're detecting this from an atmosphere that is over

1,000 light years away from us.

This is the stuff that is truly mind-boggling.

While Hannah has been looking at the planets around distant stars,

it's the planets around our own star

that, two years ago, led me to the University of Leicester,

just after some astonishing pictures were hot off the press.

Just a few days ago,

this image of Jupiter was released.

And what I love about this image

is that it shows an old friend in a new light,

with Jupiter's belts and the Great Red Spot

glowing in infrared light.

Since then, JWST has taken a closer look

at all four outer planets in our solar system.

And George is off to find out

what they've revealed.

As an exoplaneteer,

I usually spend my time studying planets orbiting distant stars.

So, it's kind of nice for a change of pace to learn about

what's going on with the planets in our own solar system.

I'm meeting Professor Leigh Fletcher

to find out how the last two years have been for him.

Welcome to Leicester.

Thank you so much. It's so good to be here!

So, first of all, I just want to remind you of what you said

last time we were here. OK, all right.

So, tell us about the other planets. What will we see?

Uranus is coming up in August and September.

Saturn is coming up in October.

And Neptune, we're going to have an opportunity to do that

in 2023 - so about 12 months.

It is a tremendously exciting time.

And it's going to keep us with sleepless nights

and heavy workloads, I think, for at least five or six years.

You said "sleepless nights and heavy workloads" -

has that become a reality?

Gosh, that feels like a lifetime ago as well.

It's been a couple of years now since we filmed that,

and, honestly, all of our dreams came true.

We got all of the data sets that we were planning

when Chris and I spoke... Amazing.

..and the data sets have confounded us, confused us,

got us excited.

We're going to start with Jupiter.

So, I hear you've had a few surprises -

pleasant ones, though.

Yeah, I think, you know, if you think about the Jovian system,

you might ask the question quite reasonably -

we've been there before, we've sent missions there -

what else can JWST really tell you?

And even I was surprised when we got some of these data back.

So, on the screen behind me

is one of JWST's fantastic images of Jupiter. Mm.

And what we can do is, when you look at Jupiter over several hours,

you can see all the cloud features moving around.

We did it at a different wavelength of light,

and one that you can only really access with JWST.

And, lo and behold, out pops a brand-new jet stream

that's gone hidden from Earth view

for the last four decades of observations of this planet.

And it was just there waiting for us in the data.

So, my colleagues published this last year - and what this is,

is a very powerful stream of air

high above the Jovian equator

that is somehow linked to the atmosphere high above.

And this is something that was completely unexpected

when we first started inspecting these data.

Seems we've learned a lot about Jupiter's system. Mm-hm.

Have we learned anything new and exciting about Saturn so far?

On the screen behind you is the first image

we captured of Saturn.

The atmosphere looks fairly bland there, but the rings

are absolutely resplendent in these data. Stunning.

We saw that the rings are

astonishingly pure, crystalline water ice

with just a tiny, tiny fraction

of things like organics peppering the rings

to give them their glorious colours.

We saw that the atmosphere of Saturn,

which is seasonal, and we had a prediction that

the atmospheric flows on Saturn would shift direction,

and those predictions were borne out quite accurately.

While Jupiter and Saturn are building a more detailed

picture of their systems,

it is the two most distant planets that have Leigh and his colleagues

relooking at their models.

So, now what about our two big enigmas, Uranus and Neptune?

So, you have to remember that

Uranus and Neptune have only had a single fly-by mission,

the venerable Voyager 2, back in the late 1980s.

And since then, we've been observing with ground-based telescopes,

with the Hubble Space Telescope.

And we thought we were starting to generate a decent

understanding of these worlds.

And, unfortunately, when we started to apply our models

based on all that prior knowledge to the new JWST data,

we started to realise something wasn't adding up,

something was missing.

It was like making a cake and having all of the ingredients for the cake,

but then, when you actually taste the cake, there's something just

not quite right in the flavour.

And it's that missing ingredient in our spectral models

that we're trying to pin down at the moment.

But that's exciting, right?

Because it means that we are going to learn something fundamentally new

about the chemical composition of these two worlds that

we didn't expect to be even asking about

when we first launched JWST.

Research continues on Uranus and Neptune,

but this was to be expected.

Leigh did say there was about six years' work to be done,

and we've come back after just two.

But it's still amazes me just how much JWST is changing

our understanding of objects around our own sun.

The solar system is our home planetary system,

and we've been studying it with telescopes for a while now and,

you know, staring at it for thousands of years.

Is it surprising that there's still so much more new stuff

to learn about it?

I think, whenever you have a brand-new capability like JWST,

there's always going to be something, some wavelength of light

that's going to deliver something that surprises you.

And you're absolutely right,

the solar system has been fabulously well studied,

but some of the questions that we're trying to answer now,

like little pieces of a jigsaw puzzle,

they add up to a much greater, much more impactful

and deep understanding of this wonderful solar system

that we're a part of.

Well, thank you so much for having me.

It's been so great chatting to you. Always a pleasure to have you.

Well, look forward to next time. OK. Take care. Bye-bye.

While Maggie and George have been catching up with scientists

we met two years ago,

I've headed to the University of Cambridge's

Kavli Institute of Cosmology,

where a fetching set of 1:1 scale replicas of JWST's mirrors

can be found.

Because light can travel through the universe for millions,

or even billions of years,

our telescopes are time machines, showing us the past.

And, with its 6.5-metre mirror,

JWST is allowing us to peer back further

than we ever have before.

I'm meeting Dr Sandro Tacchella,

who studies these very young galaxies

to find out what has been revealed.

Hey, how are you?

Hi, Chris, good to see you. Nice to see you. Thanks for having us.

You're welcome. Well, I'm excited by this.

What did we know about the early universe before JWST?

What have we learned from all of those years of pointing

at these things with the Hubble Space Telescope?

Yes, so Hubble gave us really already a very good overview of

what happened in the universe

through most of cosmic time, which means that we are, you know,

looking at the universe of the age at about two to three billion years.

That's pretty good. That's pretty good indeed.

But the growth at earlier cosmic time -

so that's in the first billion years -

is actually the most active growth and the most interesting growth,

in that sense, because that's where the very first stars,

the very first black holes and the very first galaxies

started to form and to assemble.

And it's this early universe,

when galaxies and stars were first forming,

that JWST is showing us for the first time.

Scientists around the world are working together to build

a detailed map of the deep cosmos

as part of a project called JADES -

the JWST Advanced Deep Extragalactic Survey.

Well, I think what we should do is take a tour of some of the data.

So, you've got an interactive tool? Sure, yes.

What you see here is a mosaic.

So, these are basically over, you know, 400 images that

we have taken over the last two years

with the James Webb Space Telescope.

And we have put them together.

You know, one of the very interesting structures

is what we term the cosmic rose,

OK, and you might see why.

So, when I zoom in here, you can see that this looks like,

you know, a rose-like structure.

And so, this system is actually very distant,

formed about two billion years after the Big Bang.

And what you see here is not just a single galaxy,

but actually a whole group of galaxies.

But JWST has been able to look back at even younger galaxies.

So, are there other places we should visit in this image?

So, this is one of the deeper patches in the image.

And what I'll show you here is a galaxy,

which seems to be kind of this yellowish colour. Yeah.

And this is basically the most distant galaxy

that is known to us. That splodge there?

Yeah, that splodge here.

So, it's really probing, basically, the earliest structures

we know in the universe.

This is the furthest back in time we've ever seen,

showing us the very earliest moments of our universe's story,

fewer than 300 million years after the Big Bang.

So, when you look at this image,

there are lots of splodges all over the place.

What made you look at that one in particular?

We have been seeing this object already in the very early data

we obtained nearly two years ago.

And I think the surprising thing was that it's actually very bright.

And so, our initial reaction was,

"Well, it cannot be that distant because it's too bright."

And so, we took better data -

in particular, we also took spectroscopy.

And we could clearly see that, no, that galaxy,

this yellow blob here, is really this most distant galaxy

that we have ever seen.

So, if this is the record-holder,

how common are galaxies like this?

Yes, so we don't know at the moment.

Er, it's really...

It's basically far off than whatever we have seen before.

And so, in that sense, this galaxy is very peculiar.

It's really bright. It's a very early cosmic times.

And so, it's a really one-off record-holder at the moment.

But it might be that, because we have been biased in

the way of how we thought about these early galaxies -

we were looking mostly for very young systems,

quite small systems -

we might have seen those galaxies, but we said, like, "Ah, no."

So we have to go back and look more carefully at those.

So, maybe they are more common than we thought.

Finding this particular galaxy may have been a surprise,

but it's just one of many that JWST is detecting

from the very early universe.

And the picture the telescope is giving us is of a young universe

full of galaxies growing quicker,

and forming stars faster, than had been expected.

How much has this early universe surprised you,

like, compared to what you thought you were going to get

a couple of years ago?

It was really, erm, surprising in the sense of

how much excitement it triggered also in the general public.

So, I think, you know, it was beyond just like, you know,

me looking at the screen and being astonished by

these beautiful images.

For me personally, I think I was surprised to see of how much -

how good the telescope works.

It's really works amazingly well.

And, you know, like, the images are beautiful,

but we can take spectra and really learn about these, you know,

systems in really great detail that I didn't expect to, you know...

..only maybe dream about.

Well, thank you very much. It's fascinating stuff.

Thank you very much, Chris.

While the scientists we've been meeting this month

have their heads down working on the data that JWST is supplying,

Pete is in Bedford, looking up to the skies.

The pictures taken by JWST over the last couple of years

have been nothing short of mind-blowing.

And although we can't get the same level of detail

a million miles away here on Earth,

we can find the objects in those iconic JWST images.

While what we can get from our back gardens may not compare,

the planets are slowly moving out of the sun's glare

and will become spectacular at the end of this month.

In particular, an early-morning view

low over the east-northeast horizon

before sunrise

will reveal bright Jupiter,

brightening Mars,

and binocular-dim Uranus

against the wonderful

stars of Taurus.

At the end of July,

the waning crescent moon moves

through this region too,

presenting a lovely scene

just asking to be photographed.

Saturn is further to the west of this group,

with dim Neptune in tow just to the east of it,

Saturn will be reaching its highest position in the sky

due south under relatively dark conditions during August -

this being the best time to get a steady view of the planet.

One of the most popular images taken by the Hubble Space Telescope

was that of the Pillars of Creation.

JWST took that iconic image

to another level.

While you may not be able to see the Pillars themselves

unless you have a large telescope,

you can see the nebula in which they're located -

that's the Eagle Nebula.

Now, this is best seen in the summer months,

when it's at its highest position above the southern horizon,

under dark conditions.

The Eagle Nebula can be found

by first identifying Altair,

the southernmost star

in the Summer Triangle asterism.

This is the brightest star in Aquila - the Eagle.

Locate Delta Aquilae in the centre below and right of Altair.

Extend the line from Altair

through Delta for three times

that distance again,

passing through the diamond-shaped constellation of Scutum -

the Shield - as you go,

after which you will find the Eagle Nebula -

known as M16.

Through small and medium-sized telescopes,

the Eagle Nebula appears as a cluster of stars,

the faint nebula gas being hard to see.

Long-exposure photography or a large scope

are needed to reveal it properly.

While you're in the region,

look slightly south of the Eagle Nebula

to see the Swan Nebula - M17.

This is much easier to see.

It's wonderful to think that with amateur telescopes

or even just your eyes,

you can see the same objects

as the most powerful telescope sent into space.

Sure, we can't see the same level of detail,

but it's nice to be reminded that,

as we send telescopes deeper and deeper into space,

we're all looking at the same universe.

As ever, if you get some images,

do share them on The Sky At Night Flickr,

and we'll pick some of our favourites

and show them next month.

Further details can be found at...

In the meantime, here are some of our favourites from last month.

JWST can do so much with a single image.

It can astound, amaze and surprise us.

And so we thought, before we go,

we'd show you a few of our favourite images.

This is mine.

It's the Cigar Galaxy - M82.

What you can see is a powerful wind sweeping away from the galaxy,

driven by the star formation

that's happening at the galaxy's heart.

This is my favourite JWST image.

It shows you the Goods-North region.

It has been imaged with JWST in nine different filters,

and what you can see here are about 50,000 different galaxies.

But there is one particular galaxy that is highlighted.

This is GN-z11,

this is the most distant galaxy with a known black hole.

So, this is my favourite JWST picture.

It is actually a spectrum

which includes the JWST information

from the clouds in the atmosphere of WASP-17b,

and the information that we had previously from

the Hubble Space Telescope.

So, this is my favourite JWST image.

And it is, believe it or not,

the Horsehead Nebula.

It's looking over the very top of the horse's head,

which has been an object very iconic to me,

as I've been growing up with astronomy.

So, this image is blowing my mind because,

as JWST is looking over the top of the Horsehead into deep space,

what can it see?

Galaxies.

It's an incredible image.

This is my favourite picture.

This is an image of HIP 6546 b.

Now, actual images of exoplanets are a rarity,

because direct imaging is so hard.

But this was JWST's first attempt at direct imaging -

and we got this stunning picture in four different colours,

which is marvellous.

So, I think my favourite image from JWST so far has been

this image of the ice giant Uranus.

I was so looking forward to seeing what Uranus and Neptune would

look like through this fabulous new facility.

So, when these images came out,

I almost had tears in my eyes.

This is a destination that humanity now needs to send

its next robotic explorer to.

And here, James Webb has captured it in all of its glory.

One of my favourite pictures taken by Webb so far is this one,

and it's because of a few different aspects.

Firstly, I love the beautiful images,

but this is raw data.

Secondly, it was taken by NIRSpec,

which is one of the instruments that I worked on.

And thirdly, this is showing one of the earliest galaxies

that ever existed in the universe.

The fact that we can build an instrument that goes up in space

and tells us this level of detail

is still quite mind-boggling to me.

If this is what JWST has achieved in just two years,

its potential over the next 10, or even 20, must be enormous.

I can't wait to find out what it's going to tell us.

In the meantime, we're filming our annual Question Time show

in a few months.

So, if you have a question for this year's expert panel,

go to our website right now to find out how to submit it.

Until next time, goodnight.