Predict
Published in

Predict

How Big Is Our Galaxy

What if someone travels from one end to another end of the galaxy?

How Big Is Our Galaxy
Photo by Jeremy Thomas on Unsplash

Our earth is floating in the whirlpool of millions of stars in the sky. And how big the spread of the stars is, it is unimaginable in the skin. Looking at the open cloudless sky of a village at night, the drops spread from one end of the sky to the other can be seen as bright white clouds. This is actually part of our galaxy MilkyWay. The galaxy seems to be the milk spread across the sky. That’s why the Milkyway was named by ancient people. Of course, there is an interesting story behind this name in Greek mythology. Anyone interested in can read that from here.

The shape of our galaxy

We see very little parts of the Milkyway Galaxy with empty eyes. No matter how hard you try in the dark night, you will never see the whole of our galaxy. Because we live inside this galaxy. There is an ancient proverb, the insect inside the fruit does not recognize or see the whole fruit. We are in the same situation. For the same reason, you will never see the whole city from the front door of your house. Only a little part of the town can be seen from your doorstep. But somehow, if the Milkyway galaxy was seen from above, called Birds Eye View, it would be a great adventure. In that case, the bright whirlpool of numerous stars could be seen. They’re four spiral arms shaped like a pinwheel or wheels spread around each other. Such a twisted or spiral is the position of our Earth or Solar System on the inner end of an arm.

One of the four arms of the Milkyway is called Orion. This is where our sun is located. Considering the center of the galaxy and the outer scope of the galaxy, the Sun is staying at two-thirds of the range from the center. The distance of the sun from the center of the galaxy is about 30 thousand light-years. The Sun is one of the billion rotating stars of the Milkyway.

Traveling with the speed of light

If you want to explore the whole galaxy with the fictional spaceships shown in science fictions, you’ll need a quick renovation. We should not have the speed of the current conventional rocket, at least that spaceship must have the ability to move at the speed of light. However, no one knows whether it is possible for us to achieve this speed or not.

If you walk at the speed of light, you can cross about three hundred thousand kilometers in just one second. Then you can travel around the earth seven times in just one second. You can go to the moon and return to your home in just one and a half seconds. You can visit Mars in just 20 minutes.

How much time will take to travel to the nearest star?

The closest star to the sun is called Proxima Centauri. If you move at the speed of light, it will take 4 years to reach the neighborhood’s star. But if you want to go there in our highest speed spaceship at present, then it will take 5 million years. However, if any unbelievable light-speed spaceship ever comes into our hands, it’s better to think a little if you want to go from the earth to the center of our galaxy. Because it will definitely take you 30 thousand years to go. And if you want to go from one end of the Milkyway galaxy to the other, it will take you a hundred thousand years. Because the distance from this end of our galaxy to the other is hundred thousand light-years (the way light passes in a year is called one light-year). That means the diameter of the Milkyway Galaxy is one hundred thousand light-years. Our sun is roaming around the center of the galaxy. We are roaming with it with the whole solar system. As seen, the sun is rotating at 230 kilometers per second. The sun takes about 220 to 250 million years to spin a cycle around the Milkyway Galaxy. This time is called a cosmic year.

The neighboring galaxy of the Milkyway Galaxy is called Andromeda. Its distance from our earth is 2.5 million light-years. That means it will take 2.5 million years even if it goes there at the speed of light. Now you can definitely guess how far the galaxies can be from us.

The total starts in the Milkyway galaxy

Scientists predict our Milkyway galaxy has around 30 thousand crores (300,000,000,000) stars. Can you imagine how huge the number is? Let me help you out a little. Compare the number to the sand on the beach the number will be a bit understandable. Let’s catch, every sand part is a star. If you pick up a handful of sand from the beach, it’s assumed there are thousands to almost a hundred thousand of sand. So this is the number of stars you see with your eyes at night. But that would be a very small part of the total number of stars in this galaxy. You must have seen a dump truck carrying sand on the road. The amount of sand in a proof-sized dump truck could be the total number of stars in the Milkyway Galaxy; meaning 30 thousand crores. Surprisingly, the Milkyway Galaxy is not the only galaxy in the universe. There are millions of more galaxies like this. Numerous of them are still unknown to us.

Diameter of Milkyway galaxy

The diameter of our observable universe as scientists present it is about 9,300 crores (93 billion) light-years. So how many stars are there in the universe, can it be said? Whether it is true or false, there is no fault in assuming. Scientists guess there are 200,000,000,000,000,000,000,000 stars in our universe (23 zeros after 2). This is a huge number. Let’s go back to the sand to guess how big the number is. Let’s take all the stars of the universe as sand. So all the sand on all the beaches of our world is equal to the number of stars in the universe.

If your head hasn’t been dissolved by this thought, then pick sand with your fingertip. That’s also a star, our sun. If the size of our sun is equal to this sand, you will not be able to see our beloved world with empty eyes.

By now you must have understood how big our galaxy and universe are. The size of this and the number of stars in it is unimaginable. Knowing this truth, you may feel small and trivial. But until we found any alien, remember one thing, we may be nothing in the universe, but in all living beings only we understand and know where and how we are in the universe.

--

--

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store