Practice English Speaking&Listening with: Alex Young: Sun and Moon Together Again: Helio Science from the Moon

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We're gonna step away from the Earth for a little bit and talk about in my view

and some view the most important object in the solar system besides the one we

live on but the one at the center of it the Sun. The thing that powers it all, so

let's start off with the Sun we see every day is not too exciting I mean we

know that we're not supposed to look at it. It's really really bright but even if

you look at it with a telescope and look at it in invisible light unless there's

a Sun SPOT too loud too loud okay can you turn down just a little bit

unless you look at it outside of the atmosphere it's really just a big yellow

ball maybe with a sunspot or two across it but if I step out in a space and look

at the Sun with a telescope that sees wavelengths that I can't see with my own

eye this is what I see. This is the Sun and extreme ultraviolet seen from the

Solar Dynamics Observatory and you can see it's so much more dynamic we have a

huge explosion here this is billions of tons of solar material blasting away

from the earth that millions of miles an hour called a coronal mass ejection

filling the entire solar system we have a flash of light, light through the

entire electromagnetic spectrum from radio all the way to gamma rays with

enough power, enough energy to power the world for a hundred thousand years

that's called a solar flare and both of those huge eruptions create massive

shockwaves that accelerate particles at near the speed of light and all of this

stuff fills the solar system and interacts with everything in it with

planets with their atmospheres with their magnetic fields if they have them

with asteroids and comets but also with the things and the people that we put

into space with our spacecraft, with our astronauts and so we want to be

able to understand this, maybe even predict it and have something similar to

terrestrial whether. We actually call it space weather but we want to be able to

protect our assets and protect the people as we send them back to the moon

and beyond to Mars and because we have a new initiative now a new program Artemis

to go back to the moon to send the next man and the first woman to step foot on

the lunar surface we have a unique opportunity. We can now do unique science

from the moon in particular unique science to understand this beast sitting

at the inner in the beginning of us in this in the center of our solar system

and understand better the influence that it has on us and protect those people

that were sending to the moon and to Mars

so next slide please, this is actually a really nice observation so here is the

same spacecraft a different wavelength but extreme ultraviolet but look you see

this object move in front of it okay that's the moon, that's the moon

basically eclipsing the Sun we're seeing this from space and in fact we can use

this opportunity to learn things about the moon itself these images are so

detailed that when you see that shadow come past what you're actually seeing is

if you look at the bottom it's not smooth right here there are little bumps

on it you're actually seeing the moons of your see... sorry you're seeing the

mountains of the moon when you look at this edge. So using a solar telescope

we're actually learning something about the moon but we can turn this around

because the moon gives us a unique perspective, next slide please

we have some, we have a unique opportunity because sitting on the

surface of the Moon we have no atmosphere, okay

giving us the ability to observe these wavelengths of light that we can't see

from the ground on the earth because they're stopped by our atmosphere those

extreme ultraviolet or gamma rays or x-rays and also the moon does not have a

magnetic field because not only do we see the light coming from the Sun all of

those particles when they get to the Earth are affected by the magnetic field

of the Earth they actually create a very interesting complicated environment for

example creating the Van Allen radiation belts which we have to deal with as we

fly through them away from the Earth so sitting on this object orbiting the

earth we have a unique platform for us to observe the Sun and to observe the

environment around the Sun. We can look at those huge blobs of material coronal

mass ejections leaving the Sun. We can study the particles as they're reaching

the Earth as they pass by the Moon, so if we go to the next slide please

so what you're looking at here is the same explosion that I showed you at the

very beginning and we're gonna back away from that, so you can see what happens

when that object, those particles leave the Sun we have this background of

particles called the solar wind that's always flowing away from the Sun and

then on top of that you have this bigger cluster of particles that coronal mass

ejection traveling from the Sun through the solar system and eventually

interacting with objects in the solar system, here we see it passing Venus and

you'll notice the particles are actually impinging the atmosphere of Venus

directly because Venus doesn't have a magnetic field

so they're moving straight impacting the atmosphere creating a unique environment

and as they continue on and eventually reach the Earth now you see the

particles are actually moving around it okay because the Earth's magnetic field

is acting as a sort of force field protecting to somewhat the Earth

creating a very interesting and complicated environment so when we sit

on the Moon we don't have those aspects we don't have the atmosphere we don't

have the magnetic fields but there are a couple of things that are unique about

that environment, let's go to the next slide, let's actually skip ahead I want

to pass this one and just skip to this so that magnetic field of the Earth and

we're in this case the Sun is in this direction as it's coming as all those

particles are coming past us they're stretching the magnetic field of the

Earth creating this sort of elongated almost tadpole like structure we call

this the magnetosphere, there are particles around it particles building

up along the back part this is an incredibly complicated environment that

our spacecraft and the ISS is traveling through but also in order to understand

this we have a unique perspective with the Moon because in fact the Moon as

it's orbiting the Earth it's actually passing in and out of this structure

during the new moon when the Sun is over there and the Moon is directly on the

other side of the Earth it's actually sitting right in here so for about six

days the Moon orbits through the magnetosphere and allows us to sample

what's happening in this unique environment and as the Moon moves around

it we sample different parts of this whole structure we see different

characteristics different environments and eventually for a full moon it's

sitting over on this side almost completely out

what we call the magnetosphere so we have this observing platform this

natural observing platform that's moving around the magnetosphere allowing us to

sample this hazardous complicated space that we have to travel through to

measure the particles to measure the electric and magnetic fields to measure

the plasma created in this whole structure and at the same time we're

able to get a unique view of what's happening coming from the Sun as we are

orbiting moving with the Moon as it's orbiting the Earth because again we have

no atmosphere so now we can have very large powerful telescopes that we don't

have to put into a spacecraft we can actually have on the body itself to

allow us to study all that's happening from the Sun in multiple wavelengths of

light measuring different types of particles different types of electric

and magnetic fields structures to ultimately understand this kind of this

very complicated environment that we have to travel through and that we have

to ultimately live in as we bring people to the Moon and someday on to Mars so

the Moon is providing something for us that is unique and exciting to allow us

to understand the environment created by the Sun and as we understand that not

only do we get a better handle on how to deal with it how to live with it how to

travel through it but what we learn about our own Sun ultimately tells us

about other stars other solar systems and the planets and bodies that are

interacting with them so we're looking forward to 2024 and beyond as we start

to explore this new unique environment to study our star and ultimately put

other kinds of telescopes other kinds of instruments to study other stars other

aspects of not just our solar system but the universe so thank you very much

The Description of Alex Young: Sun and Moon Together Again: Helio Science from the Moon