- This interactive map lets you explore the true scale of the observable universe
- Our Sun is only one of 70 septillions stars spread out through the cosmos
Sometimes even being in a big city can be enough to make you feel small.
But looking up into the empty vastness of space, the sheer size of the universe is almost impossible to comprehend.
This incredible interactive graphic lets you explore the sheer scale of our universe, and get some appreciation for our small place within it.
As we zoom out from our human perspective we see that the city that once seemed so overwhelming is only a tiny smudge on an insignificant rock amidst billions of others like it.
And, at the scale of the Universe, we can see that the number of stars like our own is greater than all the grains of sand on Earth.
The interactive map is titled ‘Scale of the Universe’ and was created by computer scientist Cary Huang.
To see just how small we are compared to the world around us, simply scroll out and watch as familiar landmarks vanish into insignificance.
Or, to explore the world at the microscopic scale, zoom in to see everything from bacteria right down to the fundamental particles that make up the universe.
To move faster, use the slider at the bottom (or side on mobile) to zoom in and out to smaller or larger objects.
To learn more about any object you see, tap or click on any of the images which will bring up a fact box with extra information.
You can also keep selecting smaller or larger objects to zoom in and out.
As we move outwards from the size of a human, it is surprising just how fast we appear to be vanishingly small.
Even compared to objects on Earth like the Great Pyramid of Giza, humans start to appear tiny.
But as we reach the scale of planets and moons, thinking in terms of human sizes starts to become tricky.
Professor Rob Crittenden, a cosmologist from the University of Plymouth, is an expert in the formation of the Universe and studies some of the biggest structures possible.
He told MailOnline that even he struggles to wrap his head around the vastness of the Universe.
He said: ‘Comprehending such massive scales is difficult, and probably depends on the individual.
‘I can work out from a human scale and try to picture larger and larger things; that provides some intuition, but my understanding in the end is mostly mathematical.’
But even turning to numbers starts to become baffling quickly, and to see why we only need to think about our solar system.
The Earth is a ball of rock and water 7,917 miles (2,742 km) in diameter.
While that might sound pretty big, as we zoom out into the solar system it is quickly clear just how small that really is.
Diagrams of the solar system generally show the planets neatly aligned and fairly close to one another.
But the planets are only shown this way because showing their true distances is impossible in most formats.
Even the moon, which seems so close, is actually 238,855 miles (384,400 km) from Earth – more than 140 times further than the Earth’s diameter.
The distance of the Earth from the Sun meanwhile is a massive 93 million miles (150 million km).
Neptune, the last planet in the solar system, is an average of 2.8 billion miles (4.5 billion km) from the Sun, a distance so vast that light takes four hours to travel it.
But, keep zooming out and even our solar system starts to feel quite small as we see that our sun is just a tiny part of the Milky Way Galaxy.
Professor Crittenden said: ‘Within the Milky Way galaxy, our solar system is some distance from the centre, in an outer arm.’
To measure the Milky Way itself we can no longer use miles and kilometres but must start thinking in terms of light-years.
This is the distance light travels in one Earth year, which is 5.88 trillion miles (9.46 trillion kilometers).
The Milky Way itself is 100,000 light-years across, while the Sun is about 25,000 light-years from its centre.
If it helps your imagination, look at a penny and pretend that our sun is the size of that little coin.
On this scale, the nearest star to the Sun, Alpha Centauri, would be 350 miles away.
The Milky Way, meanwhile, would be more than 7.5 million miles across; that’s more than 30 times the distance from the Earth to the moon.
But the Sun is only one between 100 and 400 billion stars within the Milky Way.
To try and get a handle on that number, if you stacked up 100 billion dollar bills on Earth the resulting tower would stretch into space 28 times higher than the orbit of the International Space Station.
Zoom out even further still and you will soon find that even our Galaxy starts to look pretty small at the cosmic scale.
Professor Crittenden said: ‘Galaxies either live on their own, in smaller structures known as groups, or in larger associations called galaxy clusters.’
Due to the pull of gravity, structures like galaxies tend to be drawn together into tighter blobs of matter.
The Milky Way is one of about 30 galaxies in the Local Group, a cluster of galaxies spread over about 10 million light-years.
The Local Group includes our largest galactic neighbour, the Andromeda Galaxy which is 2.537 million light-years away.
That is so far that the light that is now reaching us from Andromeda started its journey to our eyes more than two million years ago.
This means when we look at Andromeda, we are actually looking back into the distant past.
Finally, as we pull out even further, we begin to see the largest structures in the universe revealing themselves.
At this scale, we can see that our local group is just a small neighbourhood on the outskirts of a massive structure called the Virgo Supercluster which is more than 110 million light-years across.
However, Virgo is just one of about 10 million superclusters in the universe.
At the cosmic scale, these superclusters clump together alongside individual galaxies to form sheets and walls of matter called filaments.
These are impossibly vast structures, each of which contains hundreds of thousands of galaxies, themselves made up of hundreds of billions of stars; around one of which is orbiting the small rock upon which you are living.
Our own filament, named Laniakea, is more than 500 million light-years across.
But the Universe is even vaster still.
Professor Crittenden explains that while the Universe is infinitely large there is a finite limit to what we can observe or what astronomers call a ‘horizon’.
He said: ‘The region of the Universe that we can observe is limited to our neighbourhood where light signals could have reached us in the finite age of the Universe.
‘The full Universe must be larger than this horizon, and we haven’t seen any indications that the Universe is finite; all we really know is that it is bigger than the part of it that we can see.’
The most distant thing that we can see is something called the Cosmic Microwave Background Radiation (CMBR).
‘When the Universe was young, it was incredibly hot, and there were all kinds of particles bouncing off each other, moving very quickly,’ Professor Crittenden explains.
As these particles cooled they eventually settled to 2.7 degrees Kelvin and the tiny amounts of radiation it produces gives us the final limit to what we can see.
This means that the observable universe is estimated to be 46.508 billion light-years across.
At this point, we are now dealing with numbers that are so absurdly large that they cease to lose any real meaning.
Having started with the size of a single human being, the universe is on a scale that makes even our own Galaxy fade into nothingness.
But, it is also important to remember that by looking down rather than up, our own planet can seem impossibly vast as well.
Imagine you are sitting on a beach at night; if you look up into the sky, even on a clear night you may only a few thousand stars; that’s about as many as there are grains of sand in a handful taken from the beach.
In fact, each cubic meter of sand contains 9 billion grains of sand meaning that there are, very roughly, 7.5 quintillion grains of sand on all the beaches of the world; that’s 75 followed by 17 zeros.
If you remember, there were only between 100 and 400 billion stars in the Milky Way.
However, the Universe itself is believed to contain an estimated 70 septillion stars, that’s 7 followed by 23 zeros – or 70 thousand million, million, million stars in the observable universe.
But before you start to get lost in the vastness of space, imagine dipping your hand in the sea and letting ten drops fall.
In those ten drops of water alone there were more molecules of water than there are stars in the observable universe.
Now, if you can handle any more enormity, just know that Earth’s oceans hold 1,233 quintillion litres of water.
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
