The Milky Way, The Local Group, etc
The Earth is located in the Virgo Supercluster of galaxies, definitely an exclusive neighborhood, A supercluster is a group of galaxies held together by gravity. Within this supercluster we are in a smaller group of galaxies called the Local Group. Earth is in the second largest galaxy of the Local Group - a galaxy called the Milky Way. The Milky Way is a large spiral galaxy. Earth is located in one of the spiral arms of the Milky Way (called the Orion Arm) which lies about two-thirds of the way out from the center of the Galaxy. Here we are part of the Solar System - a group of eight planets, as well as numerous comets and asteroids and dwarf planets which orbit the Sun. We are the third planet from the Sun in the Solar System.
Based on my experience this is the best guide, so program your iPhone. However, the iPhone Inter Galatic Map (the biggest available) would take a few million light years to reach anything. But this gives you an idea of where we are in the univere, and the price of your iPhone (Model 987,786,530), is 200 million dollars and will be available in about 1000 years.
All joking aside, the monumentaal picture that this suggests give you an idea why I hold the earth in such reverence.
Years of reading the NY Times, Time, The New Yorker, etc. while reading on the web of climate change closing in on the earth left me more than once in a rage. Here were the best astronomers, climatologists, cosmologists and many thousands of others warning against the warming of our home and the short time we had to do something about it.
It was obvious that the warming was real and whether sure or not, if there were a 10% chance of wrecking our home planet as an MIT engineer I would be rousing the troups to do something about this before it got out of hand. Well it has gotten out of hand and we are still doing litte. On the next page I will detail some of the warnings, but likely the most significant was Edward Teller in 1959 at a 100th anniversary of the Petrolium Institute, which supressed the information and sold as much carbon as it could.
In a separate section I will take on the more spectualitive moral issue of how we can poisen our home planet to make more money. Or, to put it another way, what defines the moral integrity of a human being.
The story of our galaxy, the Milky Way, is pretty incredible and it is one of about 1022 galaxies and on the average a galasxy would have about 1022 stars for a total of 1044 stars. It is very likely that we are not alone but reaching the nearest star that has some chance for higher forms of light would take, I would guess, three years with a good ion thruster. So we are for all practical purposes alone and if we wreck our home, there is no other place to go or a repair man to call. But we would rather have red-blue shouting matches, and terrorism attacks and war in the middle-east rather than something which I think so few people appreciate: knowledge of something new and beautiful that no one else has. (If you want to see tension in a room full of people followed by deep intense permanent joy you can watch at JPL when a Mars lander is landing itself after a year and a half of travel.)
An artist's rendering of the Milky Way. Since it is a disc shape and we are in the middle of it we have to infer what it looks like from various photogtraphs from inside and photographs of other galaxies.Note that the outer rim at the top is about 75,000 light years.
Astromers will often describe the Milky Way galaxy in which we hide out as typical and insignificaant and if we knew of all planets occupied with "higher" forms of life we might give ourselves a rating (likely on quite a few dimensions.) But we are alone as far as we know. Check out the SETI sites though the links above.
When I look at the night sky or at photographs of stars through telescopes, my sense of awe now fails me. It has been replaced by a deep sense of dread. We have failed as human beings to pay attention. Of course, in our younger days as hunter gatherers we had only our imaginations to explain stars, the sun and moon, shooting stars, etc. and these could raise a pretty intense fear. Now we have a pretty good clue and so we protect ourselves from the weather.