Where is Earth located in the galaxy?

Feb 18, 2014 by Fraser Cain, Universe Today
The Solar System. Credit: NASA

You've probably heard the saying "everything's relative". When you consider our place in the Universe, everything really is relative. I'm recording this halfway up Vancouver Island, in the Pacific Ocean, off the West Coast of Canada. And where I'm standing is about 6,370 kilometers away from the center of the Earth, that way.

From my perspective, the Sun is over there. It's as large as a dime held at arm's length. For me it's really, really far away. In fact, at this exact time it's further away than any object I you can see with the naked eye.I'm about 150 million kilometers away from the Sun, and so are you.

We're carving out an elliptical orbit which takes one full year to complete one whole trip around. You, me and the Earth are all located inside our Solar System. Which contains the Sun, 8 planets and a vast collection of ice, rocks and dust. We're embedded deep within our galaxy, the Milky Way. It's a big flat disk of stars measuring up to 120,000 across.

Our Solar System is located in the middle of this galactic disk. And by the middle, I mean the center of the galaxy is about 27,000 light years that way, and the edge of the galaxy is about the same distance that way.

Our Milky Way is but one galaxy in a larger collection of known as the Local Group. There are 36 known objects in the local group. Which are mostly dwarf galaxies. However, there's also the Triangulum Galaxy, the Milky Way, and the Andromeda galaxy… which is by far the largest, most massive object in the Local Group, It's twice the size and 4 times the mass of the Milky Way.

This video is not supported by your browser at this time.

But where is it?

From me, and you, Andromeda is located just an astronomically distant 2.5 million light years that way. Or would that be just short 2.5 million light-years that away? I'm sure you see where this is going.

The Local Group is embedded within a much larger group known as the Virgo Supercluster, containing at least 100 galaxy groups and clusters. The rough center of the supercluster is in the constellation Virgo. Which as of right now, is that way, about 65 million light years away. Which certainly makes the 2.5 million light years to Andromeda seem like an afternoon jaunt in the family car.

Unsurprisingly, The Virgo Supercluster is a part of a larger structure as well. The Pisces-Cetus Supercluster Complex. This is a vast filament of galactic superclusters measuring about 150 million light years across AND a billion light years long. The middle is just over that way. Right over there.

One billion light years in length? Well that makes Andromeda seem right around the corner. So where are we? Where are you, and I and the Earth located in the entire Universe? The edge of the observable Universe is about 13.8 billion light years that way. But it's also 13.8 billion years that way. And that way, and that way.

Andromeda Galaxy. Credit: Fabio Bortoli

And cosmologists think that if you travel in any direction long enough, you'll return to your starting point, just like how you can travel in any one direction on the surface of the Earth and return right back at your starting point. In other words, the Earth is located at the very, very center of the Universe. Which sounds truly amazing.

What a strange coincidence for you and I to be located right here. Dead center. Smack dab right in the middle of the Universe. Certainly makes us sound important doesn't it? But considering that every other spot in the Universe is also located at the center of the .

You heard me right. Every single spot that you can imagine inside the Universe is also the center of the Universe. That definitely complicates things in our plans for Universal relevance. And all this sure does make Andromeda seem close by….and it's still just right over there, at the center of the Universe. Oh, and about every spot in the universe being the center of the Universe? Well, we'll save that one for another episode.

Explore further: Looking back to the cradle of our universe

add to favorites email to friend print save as pdf

Related Stories

Looking back to the cradle of our universe

Feb 10, 2014

(Phys.org) —NASA's Spitzer and Hubble Space Telescopes have spotted what might be one of the most distant galaxies known, harkening back to a time when our universe was only about 650 million years old ...

Hubble sees stars fleeing a cosmic crash

Aug 19, 2013

(Phys.org) —Astronomical pictures sometimes deceive us with tricks of perspective. Right in the center of this image, two spiral galaxies appear to be suffering a spectacular collision, with a host of stars ...

Messier 61 looks straight into Hubble's camera

Jun 21, 2013

(Phys.org) —The NASA/ESA Hubble Space Telescope has captured this image of nearby spiral galaxy Messier 61, also known as NGC 4303. The galaxy, located only 55 million light-years away from Earth, is roughly ...

Video: Guide to our Galaxy

Nov 22, 2013

This virtual journey shows the different components that make up our home galaxy, the Milky Way, which contains about a hundred billion stars.

Recommended for you

Image: Multicoloured view of supernova remnant

10 hours ago

Most celestial events unfold over thousands of years or more, making it impossible to follow their evolution on human timescales. Supernovas are notable exceptions, the powerful stellar explosions that make ...

Ultra-luminous X-ray sources in starburst galaxies

10 hours ago

Ultra-luminous X-ray sources (ULXs) are point sources in the sky that are so bright in X-rays that each emits more radiation than a million suns emit at all wavelengths. ULXs are rare. Most galaxies (including ...

When a bright light fades

11 hours ago

Astronomer Charles Telesco is primarily interested in the creation of planets and stars. So, when the University of Florida's giant telescope was pointed at a star undergoing a magnificent and explosive death, ...

Image: Horsehead nebula viewed in infrared

11 hours ago

Sometimes a horse of a different color hardly seems to be a horse at all, as, for example, in this newly released image from NASA's Spitzer Space Telescope. The famous Horsehead nebula makes a ghostly appearance ...

The Milky Way's new neighbour

11 hours ago

The Milky Way, the galaxy we live in, is part of a cluster of more than 50 galaxies that make up the 'Local Group', a collection that includes the famous Andromeda galaxy and many other far smaller objects. ...

User comments : 12

Adjust slider to filter visible comments by rank

Display comments: newest first

Doug_Huffman
1 / 5 (5) Feb 18, 2014
Interesting coincidence of this Gee-Whiz article with the one asserting few people know the Copernican Revolution. Now we can build a continuum of "knowing"; from ouch-hot---through Copernican Revolution---through Expanding Universe---to Holographic Universe. How do you know what you 'know'?
Returners
1 / 5 (8) Feb 18, 2014
How do you know what you 'know'?


If they are like most scientists,they "know" it only because someone else told them so, from a textbook source, which itself may or may not be correct.
Doug_Huffman
1 / 5 (5) Feb 18, 2014
Called received-knowledge, the weakest sort. It's like the witch-doctor's narration.
ekim
5 / 5 (8) Feb 18, 2014
How do you know what you 'know'?


If they are like most scientists,they "know" it only because someone else told them so, from a textbook source, which itself may or may not be correct.

I seem to recall testing much of what we were learning in books in various science labs in school. All of science is testable to anybody willing to make the effort.
yep
2.3 / 5 (3) Feb 18, 2014
"All of science is testable to anybody willing to make the effort."
And spend a few billion!
ekim
5 / 5 (5) Feb 18, 2014
"All of science is testable to anybody willing to make the effort."
And spend a few billion!

Yup. My school spent billions on each and every student. But seriously, there is a lot of science between the invention of fire and the LHC. Most science can be done for a reasonable price.
Ojorf
5 / 5 (8) Feb 19, 2014
You don't need to do all the experiments already done to know if stuff works. Science builds on itself, getting more refined the higher you go. If something at a higher level works it implies that the stuff below also works.
You can prove QM & GR simply by checking if your mobile phone is operational, that should be proof enough for any rational person.
Fleetfoot
4.6 / 5 (10) Feb 19, 2014
The edge of the observable Universe is about 13.8 billion light years that way. But it's also 13.8 billion light years that way. And that way, and that way.


No it isn't, it is now 46 billion light years away, the light from it has been travelling for 13.8 billion years but the universe has expanded a thousand-fold since the CMBR was emitted.

If your really want to know where we are in relation to the neighbourhood, watch this video:

http://irfu.cea.fr/cosmography
ShotmanMaslo
5 / 5 (7) Feb 19, 2014
And cosmologists think that if you travel in any direction long enough, you'll return to your starting point, just like how you can travel in any one direction on the surface of the Earth and return right back at your starting point.


While that is a possibility, cosmologists also think that the universe could be infinite. And so far we have not detected any cosmological curvature, indicating that it is either extremely large or infinite.

http://map.gsfc.n...ape.html
baudrunner
2 / 5 (2) Feb 22, 2014
If you go out there far enough you will not do something because it is not doable, and that is bumping into nothing, because you can't bump into nothing, which doesn't exist, and which isn't there, because it is nothing. You will find the creation front, however, where time, space, and matter are creating in this expanding universe for perpetuity because there lies the beginning, which astronomers keep trying to find when they peer through their telescopes, but it is too far away to ever see and it just keeps moving farther away in any event, creating from nothing.

The idea that you will end up where you started if you go out far enough is just nuts, because you will always be moving farther away. Always.
Feldagast
5 / 5 (3) Feb 23, 2014
The reason he said we are dead center of the universe is because he is using the same perverse logic that people thought the sun and stars and other planets revolved around earth, because it was how you perceive it to be. Since you cant see past the visible edge of the universe of course you appear to be in the center, its the center of all you can see.
Whydening Gyre
1 / 5 (1) Feb 23, 2014
The reason he said we are dead center of the universe is because he is using the same perverse logic that people thought the sun and stars and other planets revolved around earth, because it was how you perceive it to be. Since you cant see past the visible edge of the universe of course you appear to be in the center, its the center of all you can see.

And THIS is Relativity...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.