NASA released its first full-color images from the James Webb Space Telescope.
And even better, we got to talk with Drs.
Macarena Garcia Marin
and Michelle Thaller right here on Launch Pad astronomy afterward.
It was 20 years in the making and we finally were able
to witness the power of this fully operational space telescope.
Unfortunately, after the livestream ended, my wife and I witnessed the power
of an extraordinary violent storm that ripped down several trees
in our backyard and knocked the power out for the next day and a half.
I couldn't look at the images, let alone make a video about them.
So suffice to say, it's been a pretty stressful week.
But we're back, the house is fine, the cats are fine,
and Webb is fully operational and its images are spectacular.
So let's talk about these full color images.
Obviously, we can't see any infrared colors at all,
so representative colors from the visible spectrum
are mapped to the corresponding infrared filters.
But the colors are doing a lot more than just making the images seem pretty.
Our brains use color to distinguish different kinds of information
in the image.
So while the colors are necessarily artificial, they're still very useful.
The first up is a portion of the Carina Nebula dubbed the "Cosmic Cliff"s.
And this image was made with Webb's Near-Infrared Camera, or NIRCam.
And holy mackerel, This is amazing!
I mean, just look at all this detail!
The nebula is located about 7600 light years
away in the southern constellation Carina.
It spans around four square degrees of the sky.
That's much too large for Webb to image all at once.
So instead, we're looking at a portion of a larger
region in the northwest part of the nebula.
Massive hot stars in the top of the image are blowing fierce, stellar winds
and ionizing the surrounding gas with intense ultraviolet light.
The winds slam into the outer walls of the bubble, causing it to compress.
It's this compression of the gas that's kicking off
star formation inside the cloud.
And that's what we see here in unprecedented detail.
In fact, this same region was imaged by the Hubble Space Telescope in 2008.
But Webb's new image goes far beyond what Hubble sees.
And that's because infrared light can pass through much of that gas and dust.
So now we can see the stars forming inside.
The really dense knots are like cocoons
that surround a protostar forming inside.
Now they're also getting blasted by the hot mass of stars above.
And this sets up a kind of paradox, because on the one hand,
the winds from those massive stars are directly responsible
for the star formation in the surrounding cloud.
But those same winds and radiation are also eroding away
the very gas that's feeding the protostars.
So what does this mean for the fate of those protostars?
Are they still going to be massive because of all the extra gas heaped upon them?
Or will they lose all that gas before they can accrete it?
Now, figuring that out is going to require some study.
And Webb lets us see the process of star formation in such incredible detail.
Now we can see wind outflows from the protostars
that are blowing bubbles into the walls of the surrounding clouds.
We can also see what looks like faint steam rising from the ridge.
This is actually ionized gas and hot dust
streaming away from the nebula due to intense ultraviolet radiation.
Protostellar jets and wind outflows appear in a yellow gold color.
They're shooting out from protostars that are obscured by dust.
But MIRI can penetrate that dust
to uncover the protostars producing those features.
For example, a feature that looks like a comet in NIRCam is revealed
by MIRI to be one cone of an outflow
from a dust-enshrouded newborn star.
At the top of the ridge, there appears to be some kind of
geyser-like features erupting.
MIRI sees through the dust to unveil the stars responsible for this phenomena.
And around those protostars are protoplanetary disks as well.
So we're going to learn so many more insights into
not just how stars form, but also how their planets form with them.
Speaking of planets, the next target is WASP-96 b.
Now, this is a giant planet with about half the mass of Jupiter.
It orbits a star., that's about the same mass and temperature as our Sun.
However, the planet orbits less than 0.05 astronomical units from its star.
Now, that's way too close for Webb to directly image,
but Webb was able to take a spectrum of the planet's atmosphere.
This is a really cool demo of Webb's Near-Infrared Slitless Spectrograph,
or NIRISS.
It has a special Single Object Spectroscopy mode
that was designed specifically for this purpose.
It works by taking the spectrum of the exoplanet
as a transits in front of its host star.
Some of that starlight is passing through the planet's atmosphere,
which in turn creates absorption lines in the spectrum.
So by subtracting the star's original spectrum out from the combined spectrum,
you're left with the most detailed infrared
spectrum of a planet ever taken.
Previous observations of WASP-96 b
suggested that there might not be any clouds in this atmosphere.
And that's really weird because the idea of a truly
cloudless planet never made any sense.
It turns out, though, that the signature of water vapor clouds
was right there in the planet's infrared
spectrum just waiting to be found.
Now, this particular exoplanet was chosen because it has a large, puffy atmosphere,
so that makes it relatively easy to get a high quality spectrum
in a short amount of time.
But with more observing time, it becomes possible to characterize
the atmospheres of smaller Earth-sized planets.
Now it'll take longer to collect its spectrum and even longer to analyze.
But in the coming months and years, we're probably going to see
the first spectra of Earth-sized exoplanets!
We also got our first image of the remains
of a dying star called the Southern Ring Nebula.
It's a planetary nebula about 2000
light years away in the constellation Vela.
And despite their names, planetary nebulae really
have nothing to do with planets at all.
They're actually the remains of stars that were once much like our Sun.
Now, as these stars die out, they begin to expel layer upon
layer of its atmosphere., until all that remains
is the collapsed core of the star that becomes a white dwarf at the center.
Initially, the outer layers were relatively thick
and they cooled to formed dust, which is shown here in red.
Because they were dense, they were escaping relatively slowly.
But as more layers escaped, its exposed
hot core blew out a much less dense
but also a much hotter and faster wind.
Now this hot wind slammed into the slower moving material and blew out a bubble.
And this is what creates the ring.
Now, the Hubble Space Telescope imaged this nebula in 1998.
The region shown in the Hubble image is the brightest part of the nebula,
which is about half a light year in diameter.
This visible image shows the hot gas that's ionized by the white dwarf.
But Webb lets us see much more of the story.
Now we can see those shells of the much cooler dust
that was expelled by the star during its late red giant phase.
But as the star was creating these shells,
it was still in a tight orbit with its companion.
The two stars stirred up the expanding matter,
causing it to overlap with previous shells in a series of intricate patterns.
Now, this image was made with Webb's Near-Infrared Camera, NIRCam.
The actual white dwarf star that created the nebula is lost
in one of the diffraction spikes of its bright companion.
And that's the thing about those diffraction spikes.
They're pretty, but they obscure a lot of data.
But fortunately, Webb imaged the same nebula with MIRI,
and now we can clearly see both stars!
But the white dwarf actually appears red in the MIRI image.
Well, it turns out this red light is coming from dust
surrounding the white dwarf.
But that's also kind of strange, because white dwarfs
aren't supposed to have any dust surrounding them.
They're supposed to blow out these hot, fast winds that clears away
all the remaining dust.
So where is this new dust coming from?
Well, it's possible
that maybe the companion star is in the early stages of its own evolution,
so perhaps it's begun to cast out some of its outermost layers.
And maybe some of that stuff has now formed dust that obscures the white dwarf.
Now it's going to take some more investigation to really know for sure,
but MIRI is also capable of taking spectra as well.
So that will help to reveal the dust origin and fill
in a lot of the missing pieces.
But either way, we're about to discover
a whole lot more about the way binary star systems evolve.
Now, the first three targets we've looked at
so far are all located somewhere in the Milky Way Galaxy.
But we were also treated to Webb's first images of other galaxies.
Stefan's Quintet is a compact group of galaxies located about 290
million light years away in the constellation Pegasus.
It turns out that one of those galaxies is actually about
seven times closer to earth and the rest of the group.
The remaining four galaxies are undergoing a series of repeated close encounters.
Hubble imaged this group in visible wavelengths.
But Webb goes a huge step deeper
by piercing the veil of the obscuring gas and dust.
We can now see individual stars in the foreground galaxy,
and that alone is just staggering because it takes this otherwise
really fluffy galaxy and just gets rid of all of that obscuring gas and dust
and just leaves the stars right there to be counted.
Meanwhile, in the main group, we see the extent of the wreckage
that these galaxies have been exerting on each other.
In the center are a pair of really close galaxies that are colliding.
Tidal forces between these two in particular are throwing
enormous streams of gas and dust called "tidal tails".
And this ignited a wave of star formation in both galaxies.
And once again, MIRI takes us even deeper.
This image includes an additional longer wavelength filter
that wasn't used in the NIRCam-MIRI composite picture.
So the addition of this new filter meant that the color assignments
needed to be rearranged.
The red indicates the dusty star forming regions
as well as other regions enshrouded by thick dust.
Blue point sources show stars or star clusters without any dust in them,
while the blue diffuse areas indicate dust
that has a significant amount of hydrocarbon molecules.
For those smaller background galaxies, green and yellow colors
represent those same hydrocarbons as well.
But those galaxies and their hydrocarbons are much further away,
which means they're redshifted more.
But my favorite thing about this MIRI image is how insanely bright
the nucleus of the top galaxy suddenly becomes!
Now this galaxy's black hole is actively accreting material
and blazing with the light of 40 billion suns,
yet we would hardly notice at visible and even near-infrared wavelengths.
And that's because of all of the dust that surrounds this black hole.
But MIRI sees right through this dust
to unveil an incredibly active galactic nucleus.
And it gets even better
because MIRI got spectra of the gas surrounding the black hole!
The upper circle represents part of the black hole's wind outflow.
And this is material
that's getting pushed away by the powerful winds and jets from the central region.
The top spectrum from the black hole's outflow
shows a region filled with hot, ionized gases.
Meanwhile, the bottom spectrum shows that the black hole is surrounded by a disk
of cooler, denser gas of molecular hydrogen and silicate dust.
Now, this is the dust that's blocking the visible
light from the central regions of the galaxy.
We've never been able to do this kind of detailed structural analysis
before, and Webb is allowing us to examine these active black holes
and how they are feeding, in a way that we never had until now.
And yeah, get a load of all those galaxies in the background!
It's like, "Oh yeah, by the way, you did Stefan's Quinte, but here's a deep
field of galaxies, you know, if you want to have at it or anything".
But Webb can see even deeper, thanks to gravitational lensing.
This is when a massive cluster of galaxies bends the surrounding spacetime
enough to magnify and distort the light from objects behind them.
And this lets us see extremely distant galaxies
in the early Universe that would otherwise be too faint for Webb to see.
SMACS 0723 is one such cluster.
It too was studied before with the Hubble Space Telescope.
Now, in fairness, Hubble's image of this cluster was never intended
for public release., so we don't have as vibrant a color palette here.
But Webb reveals so many details
that Hubble would never be able to see at visible wavelengths.
The cluster itself is about 4.6 billion light years away.
The cluster's gravity magnifies, distorts, and sometimes creates
mirrored images of individual galaxies in the background.
Some of those lens galaxies are as far as 12 billion light years away.
The background galaxies are distorted into these orange arcs.
And their orange color is partly
because their light is redshifted thanks to the Universe's expansion.
So even though those background galaxies are filled with hot blue stars,
that blue starlight gets shifted all the way into the infrared!
In fact,
we can see details in these lens galaxies that we've never glimpsed before.
There's pockets of star formation, clusters of hot new stars,
and for the first time, we can now see the bright galactic nuclei
that are feeding their nascent black holes!
As before, the colors are telling us about the compositions of these galaxies.
Blue galaxies have bright stars, but very little dust in them.
Red galaxies have very thick layers of dust, but fewer visible stars.
Green galaxies have those hydrocarbons and other chemical compounds.
But if a picture is worth
a thousand words, a spectrum is worth a thousand pictures.
For example, consider these two arcs.
Are these two galaxies in the background, or are they
two images of the same background galaxy?
Well, there's really no way to know, just by looking at the image.
But the NIRISS spectrograph takes the spectrum
of every object in the frame simultaneously.
When the spectrum of these two images are compared to each other, we find that
not only do they have the same emission lines at the same wavelengths,
but both sets of those lines are redshifted by the same amount.
That means we're actually looking at two distorted images of the same galaxy!
In fact, the NIRSpec micro shutter array observed 48 galaxies
at the same time, and we can see a few of those spectra here.
All of them display the same
hydrogen and (oxygen) emission lines, but at different wavelengths.
And that's because the farther away these galaxies are,
the more those emission lines are shifted to longer infrared wavelengths.
The highest redshift is coming from this faint
poof of light that's barely visible in the Webb image.
And this is a tiny proto galaxy
seen when the universe was less than 1 billion years old.
Think about that for a minute.
The light from this galaxy traveled for 13.1
billion years before ending its journey on Webb's detector.
These
observations marked the first time these particular emission lines
have been seen at such incredible distances.
And by the way, this is only among Webb's first observations;
there could be even more distant galaxies in this very image.
In fact, they're already calling this image Webb's First Deep Field.
Now, to put that into some perspective, the Hubble Space Telescopes Ultra Deep
Field took 11.3 days of exposure time alone.
This image took Webb 12 and a half hours.
Now, that's not a knock against Hubble, but rather it just reflects the reality
that these distant galaxies are so redshifted that more of their light
is showing up in the infrared than it is in the visible.
And Webb's got a really big mirror to collect those infrared light photons.
So every field that Webb takes is a deep field.
And this is only the beginning.
Remember, we've got some 20-odd years of this stuff
coming down ahead of us, and we're going to need the most brilliant minds
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