The night sky has always been humanity's most ancient time clock.
The movement and absence of the sun guides the day and night. The months are measured by the
phases of the moon, and every season begins with a solstice or equinox. As the spring
season approaches in the northern hemisphere the days grow longer and the nights become shorter
until we meet the day of the vernal equinox, which is also called the spring equinox.
In this video we will explore the concept of the spring equinox. Why it happens and how the
star patterns in the night sky will shift as the seasons change. Welcome to learn the sky! My name
is Janine and I'll be your guide as we explore the night sky together one constellation at a time.
What is the spring equinox? The spring equinox is considered the first day of spring and one of the
two days of the year in which the day and night are of equal length. If you break down the word
equinox it comes from the latin word Aequi- which means equal and -nox which means night. The word
vernal is also derived from latin and it means spring. So if you recognize the root words of
vernal equinox it can help you remember that it's the time of year where the day and night are of
equal length marking the first day of spring. From the celestial viewpoint an equinox event
is when the earth's tilt and orbit around the sun align its axis neither away nor toward the sun.
During this time the sunlight shines directly on the earth's equator. For the spring equinox
this date usually occurs after mid-march and it marks the first date of spring. In the second
equinox this happens after mid-september and it marks the first day of autumn.
The experience of vernal equinox will be different depending on which hemisphere you live in.
I'm located in the northern hemisphere, so for us the sun is rising earlier now and nightfall
comes later. tThe temperature starts to increase and it is much more comfortable to go outside.
Life everywhere is beginning to reawaken. Meanwhile, south of the equator they experience
the opposite effect. The temperatures begin to cool and the days start to get shorter
as the nights get longer. The trees and plants are ending their cycle of growth and it's like
nature's last blast of energy before the winter comes. From the stargazers perspective the star
patterns and celestial objects begin to shift as well. The milky way is no longer present in the
sky during the spring months and this allows us to peer deeper into the universe. Springtime provides
an awesome opportunity for us to see far away galaxies in particular, however magnification is
needed if you want to see these distant galaxies. The constellations we begin to see include Cancer,
Leo, Virgo, Corvus, Boötes, Corona Borealis, Coma Berenices, Hercules, Lyra, Ophiuchus, and serpens.
There are some other gorgeous celestial objects to see in the springtime besides galaxies. My
favorite is the Beehive Cluster located in the constellation of Cancer, sometimes it's also called
messier 44. There's another open star cluster called messier 67 in Cancer as well. Sometimes
this one is called the Golden Eye Cluster. In terms of globular clusters Messier 13 is located in the
constellation of Hercules and here is a little bit more realistic picture of what it would look like
if you were to look at it through a telescope or a pair of binoculars. Now back to galaxies
the Virgo Cluster is located in the constellation of Virgo and it's the closest cluster of galaxies
to the Milky Way. Another group of galaxies would be the Coma Cluster and this contains over 1,000
galaxies estimated to be 350 million light years away, and the constellation of Coma Berenices
has some very interesting objects, besides just a galactic supercluster, it has a globular star
cluster other galaxies to point out and an elliptical galaxies. So it's really interesting to
take a look at the spring sky because all these deep sky objects, especially galaxies, come through
during the springtime since the Milky Way is absent. In the final portion of this video we'll
review over some of the asterisms that you can see in the spring sky. There are quite a few of them.
Remember that asterisms are simple star patterns that can be used as guides to the night sky.
We begin with the Spring Triangle, which consists of the three bright stars Arcturus, Spica, and
Regulus, and those are part of the constellations Boötes, Virgo, and Leo. The Spring Triangle asterism
can morph into the spring diamond if you include the other star. The bright star in the spring sky
called Car Caroli, and if we take a look at some pictures in order to help us navigate this this
is a large field view of the night sky here are all the constellations and if you if we back up
here what are the three brightest stars? Well for me I see this right here. So if we point out all
the constellations and then that's exactly where the Spring Triangle is and then the Spring Diamond
would be there. Another asterism that can be seen is one that's called the sickle and it's located
in the constellation of Leo. The other constellations that are nearby include
Cancer and Virgo. The Kite asterism is really just another name for the constellation of Boötes and
right next to the kite is the constellation Corona Borealism, and the other constellations that you
can use to help you find the Kite include Ursa Major. You can use the handle of the big dipper
to arc to Arcturus, which is the brightest star in that constellation, as well as the asterism
and right next to the Kite is the Northern Crown, and the Northern Crown is known as Corona Borealis.
It's exactly pretty much the same star pattern and it's a very easy constellation to see in the sky.
The Keystone is another asterism that's located in the constellation of Hercules
and this is where Corona Borealis is, just to give you some perspective, and
Hercules, if we were to point it out, is a large constellation that spans a good
portion of the spring sky, but the Keystone can also morph into the Butterfly asterism
was just another larger portion of the Keystone, that's really just the body of Hercules.
In the constellation Hercules this would kind of be Hercules head, he's holding a club ,
sometimes he's pictured holding um a lion that he captured or that he defeated in greek mythology.
So again if we were to back up here without those markings here is the Keystone and then
here is the Butterfly, right there. Our final asterism will review over is the Southern Cross.
Now if you live in the northern hemisphere this is not a constellation you'll really be able to see
unless you live in the lower latitudes, such as 20 degrees north and lower, then you'll be able to see
the Southern Cross, but that's where the Southern Cross is in the sky. When I was living in Hawaii
it was very easy to see and it was visible right around the springtime, and the southern cross is
part of the constellation known as Crux, and I've got one other beautiful picture that I just love
and I had to share with you. You can obviously see the Southern Cross right there. This
concludes our video about the Spring Equinox. I hope it was helpful for you to understand
why it happens and what the experience is like depending on where your location is. I know the
focus of this video is mostly constellations in the northern hemisphere, since that is where
I live, and please keep in mind that pretty much every constellation I mentioned in this video has
a video of its own on my spring constellations playlist. So please be sure to go check it out
if you want to dive a little bit deeper into some of the constellations of the spring sky.
Thank you so much for watching! Let me know in the comments, What is the spring equinox
like in your area of the world? For me personally I love this time of year because it marks the
return of spring and I just love seeing the emergence of the color green everywhere with
the trees coming back to life and just beautiful flowers everywhere. This community of star gazers
includes people all around the world so feel free to share your own unique experiences, as always I
encourage you to go outside view the stars take a friend or pet with you and keep looking up.