Heat. Heat.
Heat up
here.
Heat up
here.
Heat.
Heat. Heat.
Heat.
Heat. Heat.
I got
you.
Heat. Heat.
Heat
up
here.
Heat.
Heat. Heat.
Heat.
Oh,
hey.
Heat.
Come on.
Heat. Heat.
Heat.
Today is a very special day for our
planet. I'm Alex Mccoan and you're
watching Astrome Live. It's 6:30 p.m.
BST on the 12th of August, 2026
and we are about to be treated to one of
the most extraordinary sites it's
possible to witness here on Earth, a
total solar eclipse. We're bringing you
a live feed of the whole event from
ISA's telescopes in Teru, Spain. As this
cosmological phenomenon sweeps the
globe, we'll reveal how eclipses in the
past have shaped our understanding of
not just our solar system, but the
entire cosmos and explore why total
solar eclipses are even today still
vital for researchers studying our sun.
This eclipse has actually already
started. In parts of Greenland, totality
was 10 minutes ago. But here in Spain,
where the last total solar eclipse was
more than a century ago, the excitement
is building fast. We are expecting first
contact in around 5 minutes time. At
first, a small dark notch will appear
along the edge of the sun. If you
weren't looking for it, you'd miss it
completely. But gradually, the moon will
sweep across the solar disc until it
completely blocks the sun from our view.
Daylight will fade. The birds will stop
singing. The world around us will take
on an unfamiliar, eerie quality for a
few short minutes until the moon moves
on. Of course, totality will last less
than 2 minutes. But in those minutes, we
will witness one of the most
extraordinary alignments in the solar
system. A phenomenon that has shaped
centuries of discovery and revealed
secret
to share with you about eclipses and the
scientific discoveries being unlocked by
those studying them. So, I'll be
stopping in every now and then to tell
you more. Some of the Astram team are
also online right now and ready to
answer your questions. So, if you have
any, please do ask away. We're looking
forward to chatting. Now, I said this
was an extraordinary alignment, and I
mean just that. While total solar
eclipses are possible on other planets
in our solar system, Jupiter, Saturn,
Neptune, Uranus, and Pluto can all
experience this phenomenon, eclipses on
Earth are different. This is because of
an incredibly unusual coincidence. The
sun is around 400 times wider than the
moon, but it is also around 400 times
further away from us. So when the moon
comes between us and the sun, its disc
covers our star almost exactly. Although
in this instance, the moon was at
perigee, its closest point to the earth,
only 2.2 days ago. So it's a little
bigger to us than average, which is a
good thing in terms of being able to get
a long viewing time on the solar
eclipse. But we won't always be this
lucky. The Apollo 11 astronauts place
reflectors on the moon, which scientists
still use today, to give us extremely
accurate measurements of how far away
the moon is from us. That data has shown
us that the moon is getting 3.78 cm
further away from us every year. And
that means that eventually it will be
far enough away from us that a total
solar eclipse is no longer possible. It
simply won't be able to cover the entire
solar disc. For now though, let's enjoy
it whilst we can and wait for first
contact when the moon's edge first
touches the sun.
Heat. Heat.
So that's it. We have first contact. The
eclipse has officially begun. At around
4:00 on the solar disc, a tiny
imperfection has appeared. A small black
notch on the sun's otherwise perfect
circle. If you want to see this for
yourself, you will need specialist
eclipse glasses to look at the sun
safely. But if you don't have those, you
can always try finding a tree. As the
sun shines through its leaves, the tiny
gaps between them act as natural pinhole
projectors. Each opening captures the
shape of the eclipse sun and casts it
onto the ground below. And if you don't
have a tree nearby, you can do the same
thing at home with a colander from your
kitchen. If you hold it in the sunlight
and look at the shadow it casts, you
will see the same effect. As the eclipse
progresses, instead of ordinary circles
of light, there will be hundreds of tiny
cresants scattered across the ground.
Each one a miniature image of the sun.
And as the moon advances, those cresants
will grow sharper, thinner, and more
pronounced. From here on in, it's just
under 50 minutes until totality, so
you'll have plenty of time to give that
a try. Now, this might seem
counterintuitive, but we can't ever see
as close to the sun's surface as we can
during a natural total solar eclipse
like this. When you look at a disc to
block out the direct light from the sun,
whether that's the light blocking disc
in a man-made coronagraph or the moon,
light waves defract around the edges and
obscure the inner parts of the corona.
But you can reduce this effect by moving
the disc further away from the detector.
I'm sure you can see where I'm going
with this. It would be pretty difficult
for us to create a disc bigger than the
moon and put it even further away from
the Earth than our moon is now. So
natural eclipses like this with the moon
helpfully only just obscuring the sun
are our best chance to study the region
where the corona meets the sun's
surface.
Prober 3 mission is probably our closest
next bet when it comes to viewing the
corona. We released a video on this
pioneering mission just a couple of
weeks ago. But if you didn't see it yet,
this probe is studying the corona vir
creating artificial eclipses, blocking
out the disc of the sun with its own
occultter on board a second craft
nearby. Probe of 3 will likely be
observing the sun at the same time as
the eclipse here on Earth, giving us the
ability to cross reference its
observations with those from Earth,
which in turn will help us calibrate
probi for mapping coronal mass ejections
in future.
Heat.
Heat. Heat.
Heat.
Hey. Hey. Hey.
Heat.
Heat. Heat.
Heat.
Heat. Heat.
We're now about a quarter of the way
into the eclipse and the moon shadow is
approaching us fast and as it does it
actually changes our atmosphere.
Totality in Spain will coincide with
sunset which should offer a beautiful
show but it also means the moon shadow
will cut diagonally through an enormous
cross-section of our planet's lower
atmosphere. Now we have to remember the
moon shadow is moving pretty fast around
2,000 km an hour. So, as it blocks out
the sun, we see a sudden drop in UV
radiation that causes a supersonic
thermal cooling wave, which creates
ripples in Earth's upper atmosphere, an
ionospheric shock wave. Think of it like
the wake behind a speedboat. These were
first postulated in the 1970s, but it
wasn't until 2017 that a team from MIT's
Haystack Observatory finally managed to
get a highresolution image of a V-shaped
bow wave trailing behind the moon shadow
by mapping electron concentrations in
the ionosphere. Teams of scientists are
out there right now trying to find out
more, using weather balloons and
temperature sensors to measure this rare
phenomenon. Even NASA is in on the
action. In fact, during the 2024
eclipse, they launched suborbital
sounding rockets into the moon's shadow
in a mission called APE or atmospheric
pertubations around eclipse path, hoping
to measure realtime drops in
temperature, electrical density, and
magnetic turbulence. By measuring these
atmospheric ripples in real time,
scientists will gain a better
understanding of how solar energy
regulates our planetary weather systems.
And that could amongst other things help
predict the weather more accurately in
future. If you want to find out more
about these balloon experiments,
Veritasium team are with them at the
moment and should be releasing a video
on them in the next couple of days.
Hallelujah.
Heat. Heat.
Heat.
Heat. Heat.
So that's 50% coverage. The moon is now
obscuring half of the sun. And as it
moves, a team from NASA are moving with
it on a WB57
highaltitude research aircraft. This jet
is flying at an altitude of 15,000 m,
lifting it far above the clouds,
following the shadow of the moon at more
than 700 km hour. By the end of its
journey, its cameras will have captured
at least 20 images per second in
multiple wavelengths of visible and
infrared light that record changes,
structures, and outflows in the corona
during the eclipse. By chasing the moon
shadow in this way, the team will extend
the window in which it's possible to
observe the corona to nearly 3 minutes,
allowing vital extra observation time
for principal investigator Amir Kaspi of
the Southwest Research Institute in
Boulder, Colorado, and his team to learn
more about how solar prominences are
formed and to better understand the
corona and how it gets heated to nearly
a million degrees.
Hey everybody.
Heat. Heat.
It is beginning to get dark now as we
are at around 75%. % totality. And this
darkness isn't just something weird to
see happen during the day. It has a
direct impact on something that has
become very important to us, solar
power. In 2015, an eclipse in Germany
caused a massive drop in solar power
generation, forcing the electricity
grids operators to switch to
hydroelectric and gas reserves as the
eclipse passed. And the baseline of
installed solar capacity in Spain is far
higher than that of Germany in 2015.
Today's eclipse won't just be about
astrophysics. Scientists will be
carefully gathering crucial data on the
electricity network here in Spain,
hoping to gain insight into how national
grids can dynamically respond to fast
changes in electricity supply in future
and protect vital power supplies.
90% of the sun is now hidden by the
moon's disc, and things are starting to
look pretty dark here in Spain. I can't
wait to see the corona. We have so much
technology studying this eclipse today.
It's hard to imagine a time when
scientists didn't have an army of probes
and telescopes to point at the sun. But
eclipses past have still given us vital
information about the cosmos. None more
so than the eclipse of 1919.
That year, British astronomers Arthur
Edington and Frank Dyson organized
expeditions to the West African island
of Principe and the town of Sorrell in
Brazil. They studied the light coming
from stars close to the sun during
totality and proved that their starlight
was deflected by the sun a tiny amount
but enough to be measured. This matched
a major prediction made by Einstein in
his general theory of relativity and the
resulting newspaper coverage made
Einstein a worldwide celebrity. I'm not
sure any of the science being done today
will have quite the same effect for his
authors, but there is still plenty to
learn about our star from this
breathtaking natural show.
as totality approaches. The remaining
cresant of light is becoming thinner and
thinner. But watch, it will not
disappear in one smooth line. The edge
of the moon cutting across the sun isn't
a perfectly smooth arc. The moon has
mountains, crater rims, and valleys on
its surface. And thanks to topographic
data from NASA's Lunar Reconnaissance
Orbiter, scientists can now map these
exact peaks in 3D. Using those maps, we
can predict down to the millisecond
precisely where sunlight will shine
through the lunar valleys during the
moment surrounding totality. From Earth,
these appear as points of light along
the moon's surface. This phenomenon is
known as Bailey's beads. They take their
name from English astronomer Francis
Bailey who observed an annular eclipse
from Scotland in 1836 and recorded the
spectacle in vivid detail. Although they
were actually first recorded by Edmund
Halley of comet fame as early as 1715.
And we get one final brilliant flash of
light before totality, the diamond ring.
And that is totality. You can see around
the outside of the moon's disc. Here we
have a stunning view of the sun's
corona. You are now looking at
superheated plasma that's trapped along
the sun's magnetic field lines
stretching millions of kilometers into
space. Right down near the sun's surface
where the edge of the moon is, you might
even see reddish loops. These are solar
prominences, dense clouds of cooler
hydrogen gas that are held up by intense
magnetic fields. They are always there,
but we can't usually see them over the
intense glare of the sun itself. What a
treat it is to see them now.
Now we're at maximum eclipse. This is
the best possible opportunity scientists
have to observe the corona in its
entirety, analyze its small-cale
structure, and study the light
distribution within. This corona is
still something of an enigma to
scientists. The sun's surface is around
5,500°
C, but the corona can reach up to 10
million°. How it can be so much warmer
remains one of the most elusive
questions in solar physics. But each
eclipse we study brings us one step
closer to the answer.
So, now we have third contact. The
corona is fading and the crescent of the
sun is becoming visible once again. That
was stunning. I'm sure you all agree.
But this is more than just a spectacle
for you and me. This has been an
important and rare chance for scientists
to study our sun, its corona, our
atmosphere, and even our power grids. I
can't wait for the next eclipse, and I
won't have to wait long. There will be
one on the 2nd of August next year
covering Spain, Gibralta, Northern
Africa, and the Middle East. And next
year, totality will be as much as 6
minutes and 22 seconds, four times as
long as we just witnessed here. That'll
be thanks to another lucky alignment of
not only the moon being close to Earth,
but Earth being far from the sun. We'll
save more on that for next year.
So with totality over. I'll leave you to
enjoy the rest of the spectacle as the
sun returns to warm the Earth. This
should be absolutely breathtaking as
unusually for an eclipse, it's sunset.
As the sun gets ever closer to the
horizon, its partial disc will become
redder and more distorted the closer we
get to sunset. The sun will set before
the moon has fully passed it, so we'll
see a partial sun setting in the
distance. Enjoy the show.
Heat. Heat.
Heat.
Heat. Heat.
la.
Nah.
Heat. Heat.
Heat.
What do you mean?
Hey.
Hallelujah.
Heat.
Hey.
Hallelujah.
Heat. Heat.
as the sun has now nearly fully set.
That's all from me. What a privileged
experience it has been to see this
unique cosmological spectacle and to
share it with all of you. Thanks for
watching, Astramm. Until next time.