# Outer Space: Its Size Is Beyond Belief

## We live our lives on the surface of a planet and have no real concept of how vast space really is.

By A B ForbesPublished 2 months ago 4 min read
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Photo by The New York Public Library on Unsplash

British spelling.

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Outer Space.

We were successful in sending men to the Moon and back.

We are also contemplating sending men and women to Mars, but the red planet is just a step away when we think of the size of the solar system and is minuscule in comparison to the universe.

We are always thinking about distances, like how many kilometres or miles there are between our home and workplace or the distance we need to travel before reaching a holiday destination.

The diameter of the Earth is 12,742 kilometres, the distance to the Moon is 384,400 kilometres, and the Sun is almost 150 million kilometres from the Earth. We can understand these distances, but outer space is different, its size can be beyond our comprehension.

The American space probe New Horizons was launched from Cape Canaveral, Florida, in January 2006. Its most important objective was to fly by the dwarf planet Pluto. It achieved that journey to Pluto in July 2015, passing by the dwarf planet 12,550 kilometres from its surface.

New Horizons continues its journey through space; at this time, February 2024, it is over 58 astronomical units away from the Earth.

One astronomical unit, or AU, is the distance between the sun and the earth.

The average distance between the Earth and Pluto is roughly 5 billion kilometres. Considering the distance New Horizons had to travel, it is not surprising that it took 9 years, 5 months, and 25 days to reach Pluto.

New Horizons passed Pluto at a speed of roughly 58,000 kilometres per hour. I will use that speed in the following paragraphs.

The distance between the Sun and planet Earth is 149,597,870 kilometres or one astronomical unit. New Horizons would have taken over 107 days to cover that distance.

The Sun's closest star neighbour is Proxima Centauri; its distance from the Sun is just over 4 light-years or roughly 40 trillion kilometres.

That journey for our tiny spacecraft speeding along at 58,000 kilometres per hour would take over 79,000 years to complete, but remember, the closest star to the Sun is not very far away considering the size of the solar system.

The solar system has a diameter of 100,000 light-years or 946 quadrillion kilometres. Wow!

A trillion is 1 followed by 12 zeros; a quadrillion is 1 followed by 15 zeros. Yes, I know, these numbers are hard to fathom.

Sagittarius A* is the name of the black hole that lies at the centre of our galaxy, the Milky Way. That black hole is over 25,000 light-years away from the sun.

Once again, how long a journey would that be for our spacecraft, New Horizons? It works out at an incredible 465 million years of travel time.

Image Credit: NASA/JHUAPL/SwRI.

The closest spiral galaxy to the Milky Way is Andromeda, or M 31. On a clear night, Andromeda can be seen with the naked eye. Its distance from our galaxy is over 2,5 million light-years.

Hypothetically, if the two galaxies stayed the same distance apart, New Horizons would take more than 47 billion years to cover the distance between them, which is over three times the age of the universe.

Considering the size of the universe, the Andromeda galaxy is still in our local area. With advanced telescopes, we can now see objects over 13 billion light-years away. I won't work out how long New Horizons would take to reach these extremely distant objects; the massive numbers would make no sense to most of us.

The human race will probably never be able to leave our local area in space and go on incredible journeys to faraway places.

The speed of light is 1,080 million kilometres per hour, but only light can travel at that amazing speed. Even if we could reach that speed, it would still be far too slow. Our short lives would be over before we got very far.

You would think that there must be other intelligent life out there somewhere, but we will probably never find out for sure considering the vast distances involved.

Could it be possible that more advanced life forms have worked out a faster way to get from A to B? I think we would have heard from them if that were true.

Yes, the universe is vast. As I said, we can now see objects that are over 13 billion light-years away, but during that very long time, the universe has continued to expand.

It is estimated that at this time, the universe has a diameter of over 90 billion light-years.

I hope this short article has put the size of the universe into some sort of perspective.

The end.

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You may find my easy-to-understand stories about the universe and life interesting and educational.

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spacesciencehumanityextraterrestrialevolutionastronomy
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### A B Forbes

Someone with a lifelong passion for that gargantuan area we call the universe. I also write stories about life itself. Enjoy

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