The term Universe is derived from the Latin word ‘universus’ meaning  “whole”. But is ‘sky the limit?’ or is it limitless? Let’s find out.

Have you ever wondered how big the Universe is?

Let’s simplify the vastness by considering the distance of one known celestial object at a time. It takes us 3 days to reach the Moon, and around 25 days to reach the Sun. We need 7 months to reach our closest planet Mars, more than 1 year to reach Venus, 6 years to reach Jupiter, 7 years to reach Saturn, between 8-10 years to reach Uranus and Pluto respectively, and around 12 years to get to the farthest planet, Neptune.

Now, Neptune is 0.000475 light years away from the Earth, and the universe is around 93 billion light years in diameter! Are you getting the math?

But wait, if this feels mind-boggling, then let us tell you that the number above is only of the ‘observable universe.’ And the observable universe is just a little slice of a 5-tier wedding cake. It comprises all matter that we can see from the Earth using telescopes, spacecraft, and other mapping techniques. It is believed that just the observable universe has more than 2 trillion galaxies, and the whole universe could be 250 times larger. Yes, that’s how big the universe is, as much as we know until now.

See that little bright dot? That’s our Earth. This picture was taken by NASA’s space probe Voyager 1, as seen from a distance of 6 billion km. (Ref: Pic above)

Curious to find out the biggest things in the universe?

“The universe is full of magical things, patiently waiting for our wits to grow sharper”
– Eden Phillpotts

As rightly quoted by Sir Eden, we have been able to discover a few of the biggest entities in our universe. Jotting them down in descending order:

1 – Largest entity: Hercules-Corona Borealis Great Wall
This object was discovered in 2013 and is 10 billion light-years across. It is believed to contain billions of galaxies! You read that right. (Ref. Pic above)

2- Largest quasar collection: Huge-LQG
This cosmic collection is estimated to be 4 billion light-years across and is made of 73 quasars.

3- Largest supercluster: Laniakea Supercluster
Spread across 520 million light years, this collection of galaxies hosts our tiny home galaxy ‘The Milky Way’ along with 100,000 other galaxies. (Ref: Pic above)

4- Largest individual object: Protocluster SPT2349-56
This protocluster is around 12.4 billion light years away and will eventually combine into a galaxy that will weigh 10 trillion times more than the Sun.

5- Largest galactic farts: Fermi Bubbles
Discovered in 2010, these are massive bubbles filled with cosmic rays that emerge above and below the center of our galaxy. They are estimated to be 50,000 light-years tall. (Ref: Pic above)

6- Largest black hole: TON 618
This ultra-massive black hole possesses 66 billion solar masses, is twice as large as the Milky Way, and is as bright as 140 trillion Suns.

7- Largest galaxy: IC 1101
This galaxy is spread 5.5 million light-years across and is 2,000 times bigger than our home galaxy. Keep breathing.

8- Largest Nebula: The Tarantula Nebula

Also known as 30 Doradus, this nebula is also the most active star-forming region that stretches over 1,800 light years. It is located in a small satellite galaxy orbiting the Milky Way. (Ref: Pic above)

Will there come a time when the universe ends?

Well, some cosmic theories suggest that the universe is flat and might just keep expanding limitlessly, while other theories suggest that the universe will meet an end when the life span of all the stars ends. Since the light will fade out and darkness will take over, the universe will also come to an end. 

There are three prominent theories about the end of the universe:

1-  The Big Freeze: As per this theory, it is believed that the universe will start colling down with time while expanding. This in turn will cease all life from existing.

2- The Big Crunch: This theory suggests that the universe will eventually reverse the process, and stop expanding. It will cause a collapse and lead to the beginning of another Big Bang.

3- The Big Rip: According to this theory, everything including atoms will be shredded to the end when the dark energy becomes more powerful than gravity. 

However, what we know for (almost) sure is that these apocalyptic situations are billions of years away and we will not live to see. That should pacify us for now. 

As of today, we may have limited information about the sky, but we at least know that ‘the sky is not the limit’. Even if space is about huge distances and massive objects, it depends on what is it compared to. Our home planet Earth is 24,901 miles, which is huge to us, but the Earth is a tiny object in our solar system, leave apart the universe. 

Even if the universe is expanding on unknown terms, we are also expanding our technology efficiencies and awareness. Years ago, the world was huge, places were miles apart, and we didn’t even know if it was flat or round. But today, we have airplanes and mobile phones that shrink the world to hours and minutes. Maybe someday we will find a way to travel at the speed of light, and the universe will seem much smaller than it is today. Who knows, right?!

Wish to know how (in)significant we are?

Now we have an idea of how unthinkably big the universe is and that it is still expanding at a speed more than the speed of light. This is going on for over 14 billion years if not less.

In this huge space, where do we stand? We humans. Our appearances, our worries, our delusions of self-importance, our overall being? 

Well, we are smaller than a grain of sand, to the Universe. And evidently, we are not the center of the universe! Astronomy is an obliging experience, even with our extremely limited awareness of the universe.

Watch this video to understand better:

If you know of more interesting theories or surprising facts about cosmic space, tell us in the comments.

Information and image sources:
https://www.space.com | https://nineplanets.org | https://www.bbc.com | https://www.esa.int | https://www.theguardian.com | https://www.livescience.com | https://www.nasa.gov | https://www.forbes.com | https://www.britannica.com