Original subtitles

(expansive music)

- [Narrator] We have looked up to the stars

and galaxies in awe and wonder for millennia trying

to understand our place in the universe.

Current technology is enabling us to see further

and farther back in time with much more detail

than ever.

The next generation of orbiting telescopes soon

to enter service.

Who knows what giant leap they will make

in our understanding of the universe.

(exciting upbeat music)

(telescope zooms)

(rocket zooms)

(volcano erupts)

(text zooms)

(soft music)

Since its launch in 2013, ESSA's Gaia Observatory has

been constantly mapping our galaxy, creating

the most accurate to complete multidimensional map

of the Milky Way.

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This latest observational data set has been released

and contains even more an improved information

about almost 2 billion stars, solar system objects

and extra galactic sources.

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Our sun travels at 240 kilometers per second

around the galactic center

and will take 220 million years to complete one orbit.

The Gaia data set includes stellar positions

stars distances, and motions across the sky

plus color information, and most significantly

the radial velocities for 33 million stars

within the Milky Way.

This allows astronomers to create the most accurate

and complete multidimensional map

of our astronomical neighborhood.

Another novelty in this data set is the largest catalog yet

of binary stars in the Milky Way

which is crucial to understand stellar evolution.

At the Observatoire de Paris in Meudon, Paris France,

scientists form part

of the data processing and analysis consortium,

some 400 scientists from 20 countries who are responsible

for the processing of Gaia's data

with the final objective of producing the Gaia catalog.

- [Paola] So Gaia is extremely important

for all fields of astronomy.

The Gaia catalogs that results contain a huge amount

of information that will provide the material

for the work of astronomers in,

around the world.

And for many, many years.

(soft music)

- [Narrator] With each new release, the observed stars,

solar system objects, and extra galactic objects increase

and many more details are added

to what is already the most detailed overview of our galaxy.

- [Arenou] So Gaia is incredible satellite,

which looks at the stars

which measure 1.8 billion stars, but obviously it goes

from what is nearby asteroids

up to very distant quasars.

For this 1.8 billion stars

it's able to find their distance

their astrophysical parameters, their ID card

in some sense.

Up to now, Gaia had given already a lot

of information about, about stars, but near now

it's it going from astrometry position, motion of the stars.

But to astrophysics, knowing the characteristics

the astrophysical parameters for nearly alpha billion stars

it it is able also to

to find a lot and viable stars, to classify them.

It's able of course also to

to see what is viable in terms of position.

And so it helps to find binary stars which move

on the sky or on the spectrum earth.

- And this time we provide new measurements such

as star brightness in the (indistinct),

rotational velocities, atmospheric parameters,

chemical composition.

And the (indistinct) also provide information

on the abundance of the interstellar material

that is present between stars.

(soft music)

- So Gaia, yeah, is observing with astrometric instrument

which measures the position of the objects.

And from this position, it gets the motion

of the object with time on the sky.

That's astrometry.

Then Gaia measure also the light

of the object measure spectrometry for the object.

And from this, it can infer the color of the object

but also you can derive

from that all the astrophysical parameters that you can get

like tempera, effective temperature, gravity, and so on.

You can also infer what is the extension

of light in the distance where it comes from the star to us.

So the third instrument now is a spectrograph

which is able to see the spectrum of the star.

And so when you see the lines of the spectrum

you see at which speed the object is going

towards us or and the other way around

or when it's moving periodically, then you can detect

through the motion of this fragile velocity

that the three main instruments of Gaia.

(soft music)

(machinery whirring)

- [Narrator] Even older than Gaia

is the venerable Hubble space telescope.

It too continues to contribute to the sciences of cosmology.

(soft music)

- [Nancy] To my mind, the most important discovery

from Hubble is the discovery of dark energy.

There have been a lot of interesting discovery, certainly

oh, certainly the, the fact that there are billions

and billions of galaxies that we, we had no idea

there were that many.

The work that we were doing on exoplanets

with Hubble has been interesting.

I mean, Hubble has carried such a wide variety of results

that it's hard to pick a, a, a single one.

But I do feel the dark energy is the outstanding discovery.

And what that means is simply that space.

We always thought that space would contract

because gravity would pull it together.

We knew it was expanding, but we thought the expansion

would slow down.

Well, instead, the expansion's speeding up.

And that is a very exciting thing to me.

- [Jennifer] Because the Hubble space telescope is operating

so well and is so scientifically effective right now.

Scientists are using Hubble to investigate some

of the deepest mysteries of the universe.

One mystery is dark energy.

That's the name just kind of plastered

on this phenomena that Hubble and other telescopes together

we found that the universe expansion has been accelerating

for the last few billion years.

Well, what is causing that?

We don't know.

It's something about a repulsive force

that we may not fully understand

or new physics that we don't fully understand.

But Hubble was used along in compliment

with some telescopes on the ground to determine

that the expansion of the universe is in fact accelerating

by something we're now calling dark energy.

And without Hubble

we would've not been able to make this detection

which is now a Nobel Prize winning discovery.

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- [John] This explains why the universe appears to

be accelerating now when it used to be slowing

down because of gravity.

So now the question is, well

is this a simple story or is it complicated?

Is there the more than one kind of dark energy?

Has the dark energy itself changed over time?

- [Jennifer] So Hubble is now being used to refine

even further that expansion rate of the universe

in our current epic and trying to compare that

to what might be predicted from looking

at other measurements of the universe with other telescopes.

Right now we're finding a discrepancy

between what we might have expected

and what we're actually measuring.

So that's one realm where Hubble is really

at the cutting edge of helping us understand

or at least open up new mysteries of the universe.

(telescope zooms)

(soft music)

- [Narrator] Astronomists are still puzzling

over dark matter and how it behaves.

They have found small dense concentrations of dark matter

the bend and magnify light much more strongly than expected.

Dark matter makes up the bulk of a galaxy.

The gravitational influence of dark matter is thought to

tie the galaxies together in massive clusters.

There is so much regular matter and dark matter concentrated

in these clusters that their gravity magnifies

and warps light from distant background objects.

By studying how the light distorts the background galaxies

though this gravitational lensing, can help map where

the dark matter is in galaxy clusters.

Images of lensing galaxy clusters are filled with

the smear images of remote background galaxies.

The higher the concentration of dark matter, the more

dramatic its light bending power is.

Smaller clumps of dark matter associated

with individual galaxies in the galaxy cluster

create more distortions.

In some sense, the Galaxy cluster acts as a large lens

that is many smaller lenses embedded inside.

But strangely, astronomists found that three galaxy clusters

used in their study had concentrations of dark matter

that are so massive that the lensing effects they

produce are 10 times stronger than originally expected.

Soon to be launched, ESA's Euclid mission aims

to investigate this dark matter dark energy

and the expanding universe in even greater detail.

Euclid will image billions

of galaxies with unprecedented accuracy out

to a distance of 10 billion light years.

These measurements will enable astronomers to

improve their understanding of the expansion

of the universe and the growth rate of cosmic structures.

- [Elena] Euclid is a cosmology mission.

It will study and try to understand better understand

the geometry and the nature of the dark matter.

And dark energy, which is the peculiarity of Euclid

is a telescope that will scan the sky

with an accuracy that is unprecedented.

So this is really something that no other spacecraft

did before.

This will allow to get additional information

and to better understand the story and the for the expansion

of the universe and the role on the cosmic structure.

- [Narrator] Euclid carries a three mirror

and a stigma design.

The primary mirror is 1.2 meters in diameter.

This type of design allows for a greater field of view

covering the visible wavelengths

and simultaneously near infrared spectroscopy

and photometry.

- [Elena] Was very important milestone because is somehow

the starting point of new phase of the project

because so far the two parts that you can see

the upper part that is the payload model

and the lower part that is the service model

have been developed and tested separately.

So today with the mating, we start a following phase

next phase with both the part, the, the two main constituent

of the Euclid spacecraft are together.

- Indeed, this is a completely new design

with a lot of challenges involved with this mission.

And we have put together a team

of about 120 companies in Europe, which are working together

in good synergy for several years.

And we are very proud of the results, actually today.

- [Narrator] The mission is designed

for a six year lifespan.

However, an extension of a further five years

is contemplated dependent

on the spacecrafts onboard resources.

- [Paolo] With the meeting today of the telescope

with the service model, we achieve a major milestone

in integration of the flight satellite.

It has been a long journey

because the two element have been developed independently

for several years, and now

for the first time they are mated together.

And this make us very proud of the achievement.

- [Hans] So the telescope was already delivered here

in October last year and was put

in in the clean room on the fixture,

ready to be mount mated.

In the meantime, we, we finished the work to be done

on the remaining part of the satellite, which is here.

And today we, we released the, the telescope

from that foundation and we move it to the SVM by crane.

It was, it is a very dedicated operation because the

the tolerances of the budget

we have for the mechanical stresses is, is very small.

So it's, it's a very fragile telescope

because it need to be light.

So it's quite fragile.

So for this operation

there was a tight allocation for the stresses

and the stresses they measured at every step on the feet

which support the satellite on six points.

- Next step after this meeting will be the integration

of the solar ray sun shield

which will happen around May this year.

And at that point the satellite will be

in full flight configuration.

And at that point we go, we will go

to Cannes to conduct the environmental test campaign

for about six months.

The objective is to have the satellite complete, complete

integrated, and validated the the beginning of next year.

- [Elena] After the mating, the next step will be

the finalization of all the connection electrical testing.

Then in front of the telescope will be installed

the sun shield and the solar array.

And after that, the I-gain antenna then the

the test campaign will start in, in Cannes.

The full spacecraft will be tested

in environmental condition and

at the end it'll be ready to be shipped

to Peru for the launch campaign.

- [Narrator] Launching around the same time

as you Euclid is NASA's SPHERE X mission.

It will survey hundreds of millions

of galaxies near and far some so distant.

Their light has taken 10 billion years to reach Earth.

Also, it will search for water

and organic molecules within the Milky Way.

- [Jamie] SPHERE X is NASA's latest explorer mission

in astrophysics.

It's a small telescope, but it has this unique

and powerful capability of doing spectroscopy everywhere.

- We are going to survey the entire celestial sphere

and collect a data set that will help us

answer three fundamental science questions.

- [Jamie] It's gonna tell us about the origin

of the universe, the birth and formation history of galaxies

and the abundance of essential molecules such

as water in the early stages of star and planet formation.

- [Beth] The great thing about SPHERE X is not only will we

view the entire sky four times

but we will see it in nearly a hundred near infrared colors.

And that's really never been done before.

- [Jamie] According to our current understanding

of the universe we think that in the very earliest times

and I'm talking here a fraction of a second, much less

than a nanosecond, the universe appeared to have gone

through an accelerating expansion called inflation.

And this is really a

a profound idea and we're very interested to, to test it.

And so one way to do this is to look

at how matter is distributed over the universe.

We want to map hundreds

of millions of galaxies in three dimensions.

What SHERE X does, in addition to mapping

out all these galaxies, is we cover the whole sky.

So we can measure these galaxies

over the largest part of the, you know, range.

We can see which is the entire sky

and we want to cover the full range

of distances from today to as far back as we we can see.

- [Cooray] We know there are about

a hundred billion galaxies in the universe, maybe more,

but we still don't have a good understanding

how these galaxies came to be.

Did they all form at the same time?

Did they change in size

and luminosity or brightness over time?

So the intent with SPHERE X is

for us to figure out the formation history of galaxies.

Where do they exactly form

and how do they grow over cosmic time?

And that information is crucial for us because

that'll allow us to separate various theories we right

have right now on the formation and and growth of galaxies.

- [Narrator] SPHERE X will also identify targets

for more detailed study

by NASA's James Webb Space Telescope

and the future Nancy Grace Roman Space Telescope.

(booming music)

The Nancy Grace Roman Space telescope

is set to launch a top of SpaceX Falcon Heavy

within the next few years.

It will capture images unlike any satellite before it.

The Roman Space Telescope will have

the same image resolution as Hubble

but with 30 years of technological advancement

will cover an area 100 times larger.

Roman will also view the sky

in carefully selected wavelengths of infrared light.

This will allow scientists to see

through the obscuring dust, to reveal hidden stars

and watch the growth of galaxies

over the last 10 billion years.

(expansive music)

Because Roman will be seeing further back in time,

accurate measurement of distance stars is critical.

A small galaxy close

in looks similar to a large galaxy farther out.

One method used by astronomers to gauge distances

is something called a standard candle.

A standard candle is a type of stellar object

or event that emits a specific known amount of light.

This works because light sources appeared predictably

dimmer the farther away they are.

So for further distances, astronomers have to rely

on the brightest of stars

or events in particular exploding stars called supernovi.

There are a few different kinds of supernovi

but the best for standard candles are type one A.

These supernovi involve a white dwarf, the leftover core

of a dead star and one other star in a binary system.

The white dwarf accumulates mass from its partner

and eventually explodes giving off a set amount of light.

These beacons then allow scientists to accurately

predict their distances.

Roman will also use its broad view to search

for planets around other stars in our galaxy.

It will be fitted with a coronagraph

which reduces the light coming directly

from the star to separate it

from the light reflected by the planet.

(planet booms)

The Roman space telescope's coronagraph doesn't block

the star's light.

It uses a combination of discs with complex patterns

and light blocking stops to create destructive interference

with the stars light effectively making it disappear

while allowing the light from planets to pass through.

A complicating factor is

that the light picks up small distortions

as it reflects off the telescope series of mirrors

and these distortions can reduce the effectiveness

of the destructive interference.

Collecting more light increases the image signal

but the planets are still hidden

under blobs of leftover distorted starlight.

To remove these blobs

the coronagraph has special deformable mirrors

that can change shape by using hundreds of tiny pistons.

This corrects distortions in the light beam.

As the mirrors deformed

the blobs of light slowly disappear

revealing brighter planets.

Advanced software processes this data further improving

the contrast and clarity of the image.

This processing makes objects more

than a billion times fainter than the star visible.

As a result the Roman space telescope

will provide the first look

at individual planets

in star systems that might be similar to our own.

The Nancy Grace Roman Space telescope will also look

for the fingerprint of dark matter

and dark energy in the distant reaches of the universe.

With an unprecedented combination of breadth and depth,

it will open a new era

in observing and understanding our universe.

(eerie expansive space music)