When you look at this photo the first thing that probably stands out to you is the Milky Way band
that spans the width of the sky. This is our home galaxy, and if you seek out dark enough skies it
can be seen in the summer and winter months. I'll never forget the first time I saw the milky way
in the sky. It was during the winter time, I was in Hawaii and I was visiting there because I
was taking a three-week geology class about the geologic evolutions of the islands and I saw the
Milky Way and knew I would be back, but the Milky Way is not the only galaxy we can see with the
naked eye. Right here you can see the Small, and Large Magellanic Clouds. Those can be seen from
the Southern hemisphere, and then right here this needle-like shape is the Andromeda Galaxy,
and this is the oldest light you can see with the naked eye. It can be seen without magnification and
this video we're going to explore the similarities and differences between the Andromeda Galaxy, which
is the closest spiral galaxy to us, and the Milky Way, the one in which we live in. Welcome to Learn
the Sky, my name is Janine and I'll be your guide as we explore the sky one constellation at a time.
Before we dive into the similarities and differences of the Milky Way
and Andromeda Galaxies I wanted to go over a few pictures to make sure you know the differences
of what they look like in the sky. The Milky Way is very obvious to see. It's this big huge cloudy band
that spans across the entire sky, where Andromeda is much more smaller piece of real estate in the
sky but it has a very peculiar shape. It has this almost like a needle like shape and that's because
it's a spiral galaxy, we're sort of looking at it edge, on but a little its face is tilted towards us.
So if you can start to train yourself to look for this in the sky
when you're looking at these pictures it'll help you when you go outside. Here's another photo of
the Milky Way, you can see it spans across the entire sky. This is obviously a long exposure
photo, that's why the the light is bright here and this is like the core of the galaxy. Here we have
the Small and Large Magellanic Clouds, and this needle shape right there is the Andromeda Galaxy.
So let's take a look at one more picture, this is more of a realistic view of what you would see
if you were in a sky that's dark enough. So can you spot the Milky Way galaxy and can you see
that needle-like shape in this photo? So just to point it out to you this is where the Milky Way is,
and right there is the Andromeda Galaxy. I do have a whole video on how to find the Andromeda
Galaxy in the sky. I give you a few different strategies, so be sure to go check out that video.
Now we'll take a look at the specific characteristics of each of these
galaxies. So the Milky Way, which you can probably easily identify at this point in this picture,
it can be seen with the unaided eye, and it is a Spiral Galaxy, and if you want to see the Milky Way
it's really essential that you seek out dark skies. In terms of its size it's 100,000 light years
across in diameter, and it has 59 satellite dwarf galaxies. Two of which ones you've seen already in
this video, the Small and Large Magellanic Cloud. It's estimated that the Milky Way has between 100 to
400 billion stars, and as I said earlier this is Earth's home galaxy, and if we take a look
at this photo it's looking at the Milky Way from the bird's eye view, this is an artist's impression,
and you can see right here, this is the center of the galaxy, the Milky Way is classified as a barred
spiral galaxy. So the bar is is right here, that shape, and then the arms come out this way, and if
we were to label where what these arms are named and the distances here's what that would look like,
and our Sun, right here, is about two-thirds of the way out from the center of the galaxy, and
if we were to take a look at this from another view, you can see this is the Milky Way band,
right here, Earth would be, oops I'm over here, Earth would be over here, so it's about two-thirds of the
way out, we live in the arms of the galaxy, and then this is showing you where you have different types
of radiation that's detected, and scientists estimate that this galaxy right here UGC
12158 is the most similar to the structure of our own galaxy. So the only real pictures we have of
our Milky Way are from this vantage point, right, so this scientists estimate that this galaxy in
particular most resembles our own, and if we take a look at some of the surrounding areas
you can see these are some of the the galaxies that are um orbiting the Milky Way galaxy, here
you can see the Large Magellanic Cloud, and Small Magellanic Cloud. These are mostly dwarf galaxies.
Now we'll take a look at the characteristics of the Andromeda Galaxy. It is also a spiral
galaxy, and definitely a favorite to photograph for astrophotographers, and you can see why it is such
a gorgeous galaxy, and it can be seen with the unaided eye and it's estimated to be 2.5 million
light years away. It's estimated that it has 35 satellite galaxies, and it's said to have
the same mass of this Milky Way, but twice the size, which would make its diameter going across
200,000 light years, and it's estimated to have one trillion stars, and if we just take a look at
this picture, right here, the Andromeda Galaxy has really been photographed so much because it's it's
really fascinating to see. You can see the shape of the spiral arms. You can see some dark areas
here where gas is being absorbed and light cannot pass through. So it's really really interesting
to study, and if we zoom out here you can see here are some of the satellite galaxies that are going
around Andromeda, and when you look at Andromeda on a star map that you can see right here,
you can see how big it really is in the sky, and if you train yourself on how to find it
then you are able to see this object, and once you know where it is, you know where it is. So the
trick I use really quickly is I use um the Great Square of Pegasus, okay, I find this star I jump,
um I count one two three, and then one two three, that's how I find it, so I kind of skip along these
stars by three two times and find Andromeda Galaxy. So use that strategy to help you find it, there is
another nearby galaxy called the Triangulum Galaxy, this one is also going around the Andromeda Galaxy.
Andromeda is also known as Messier 31 and it is also a barred spiral galaxy. For me I don't truly
see the bar here, but that's perhaps because of its orientation, and then there's other satellite
galaxies such as Messier 33 and Messier 110, and here's another gorgeous picture you can see
this um because of its long shape it gives that needle-like appearance in the sky,
and you have those galaxies that are orbiting around the Andromeda Galaxy.
I've got a few other shots, I'm super fascinated with this galaxy, like many others out there, but
this shows you what the Andromeda Galaxy looks like in ultraviolet radiation. Here you can see
it in infrared, so that's like the heat. Where's the heat in the galaxy? This picture tells that story.
Here's another view of where infrared radiation is coming from in the Andromeda Galaxy. This here is a
really famous photo, um, this is the Andromeda Galaxy in visible light, and this is a long
exposure shot taken by the hubble and you can find this on the inter webs and zoom in and
just it's a really really fascinating photo. I will put the link for that and list it below,
and these these are our local groups here. I love this photo because it shows you the Milky Way, and
all the satellite galaxies going around the Milky Way, and then you have Andromeda and all of its
satellite galaxies as well, and then these two the Andromeda milky way will eventually collide
in the future, and if we were to zoom up that just shows you the variety of galaxies
that are that are in our local group, and here you can see the Triangulum Galaxy, another small
spiral galaxy that can be seen with the unaided eye, but you really need to have a very dark sky,
and the collision scenario for the Milky Way and Andromeda is that eventually within four billion
years we will collide with it. So again, we would be here, and over time these two galaxies would merge,
and I'll take a look, show you one more photo of Andromeda. I do have a whole video on that so make
sure you go see you see that video, but here you can see, probably figure out where the Andromeda
Galaxy is now that we've talked about it. Look for that shape, and here it is, right there, and actually
you can also see the Triangulum Galaxy, it's right there. So these bright stars here are a part of
Andromeda constellation. So hopefully um this gives you a good idea of the characteristics between the
Milky Way and Andromeda Galaxy. So in all my versus videos I like to use a venn diagram to
show the similarities and differences between the two things that I am comparing. So we'll start with
the similarities. The Andromeda Galaxy and Milky Way galaxy, they're both barred spiral galaxies,
they both can be seen with the naked eye, and they both have a variety of satellite galaxies
that are traveling around that main galaxy. Now in terms of the differences, the Andromeda Galaxy
is simply bigger. It's twice the size, even though it has the same mass as the Milky Way.
I probably should have put same mass here in the center, it has more stars, one trillion stars, which
is much more than the Milky Way, and its distance is 2.5 million light years away. Now the Milky Way
is smaller. It's 100,000 light years in diameter, it has between 100 and 400 billion stars, and it
is our local galaxy, we live in it. So when we look up at the sky we are able to see it. So I
hope this video was helpful for you in order to know the differences and similarities between
the Milky Way galaxy and the Andromeda Galaxy. I do remember the first time I saw Andromeda, it was
on Mauna Kea at the visitor station, and um I just moved there andIi was starting to learn
how to volunteer, and I would listen to the star talks each night, and that's how I started learning
the sky, and they taught me that trick on how to find Andromeda Galaxy. You have to use Pegasus
and Andromeda to help you find it. You can also use Cassiopeia as well, so to wrap up the Andromeda
Galaxy versus the Milky Way Galaxy. They're similar because they're both spiral galaxies, they can be
seen without magnification if you have dark enough skies, and their mass is similar. In terms of their
differences, their size is different, the number of stars, and the distances between each other.
So thank you so much for watching, I hope this video was helpful, and I wish you luck finding
both the Milky Way and Andromeda Galaxy. Remember anytime you're learning to stargaze it
really takes time, patience, and practice. So keep going outside and as always keep looking up.