Distances: Space Travel:




When I started with this hobby I was fascinated by the vastness of the distances involved, and I guess that I still am.  I have taken pictures of all of the objects discussed below which are all the way out and beyond 2 Billion Light Years from the end of my driveway and beyond 3 Billion from my observatory in New Mexico.  If I can see that far, can I get there?


Consider the distance from New York to Frankfurt , Germany .    This one-way flight takes about 8 hours travel time.  This is traveling on a 747 airplane at around 550 miles per hour.  The way to think about distance is how much time it would take to get from point A to point B?


Near Earth [The Moon]


Since we have already been to the moon (at least some of us) we know that we have a faster way to travel than a 747.  The average speed to make this trip was about 5,000 miles per hour (10x that of the 747)


Distance (one-way)

747 travel time

Saturn V Rocket


240 Thousand Miles

18 days

2 days


Within Our Solar System [The Planets]


With today’s technology travel time by space ship we can easily get to an average speed of 15,000 miles per (30x that of the 747). The most recent rocket to Jupiter for example (Juno Mission launched in 2011 with an Atlas 5 launch vehicle, and with a sling-shot speed boost from Earth) will travel at 300x the speed of a 747 or about 165,000 miles per hour. This is the fastest man-made object in history.



56 Million Miles

I don’t want to go there it is too hot.


26 Million Miles

While this is too hot also, it is our closest neighbor:

72 Days


48 Million Miles

133 Days or so… these are just rough numbers, the planets do not stand still and the distance relative to earth varies significantly.  I understand that the NASA estimate is a 9 month journey, one-way.


400 Million Miles

Why go to a place where you cannot stand and that may have no real surface?


800 Million Miles

Why go to a place where you cannot stand… sight seeing of course, the rings are pretty:

6 Years.


1.7 Billion Miles

Why go to a place where you cannot stand and that may have no real surface?


2.7 Billion Miles

Why go to a place where you cannot stand and that may have no real surface?


3.5 Billion Miles

9 Years, but you might have to jump off the rocket as it fly's on past Pluto.





What does this mean?  Mars yes, and maybe someday Venus.  Human beings will definitely land on Mars in this century.  But for the rest of the planets themselves, there would be no purpose for human travel.  For the planets other than Mars our machines would have to do the work.  We will someday probably find some of the moons around Jupiter and Saturn to be worth the trip.  And if this is interesting enough then there may be other interesting moons around the more distant gas giants.  But if Pluto is too far to go, how will humans ever explore beyond our Solar System?  There can only be a couple of possible answers either travel much faster, or invent some other exotic method (worm holes, bending space, etc).  And as for extra-terrestrials, if we cannot get there because of the laws of physics, they probably cannot get here either.


Within Our Galaxy (the Milky Way) [Nebula, Planetary Nebula, Star Clusters, Stars, Comets, Asteroids etc]


The real problems just begin when we want to think about traveling to other places within our own galaxy (to other planets outside our solar systems for example).  Instead of referring to millions or billions of miles we must switch the scale and talk about light years of distance.  The distance that light travels in one year (1 light year) is about 5.8 trillion miles.  There is just no way to even begin to get there from here.  Let’s assume that we could build a really fast rocket that goes 2,000x our 747-airplane and can average 1 Million Miles an hour.  Using this new rocket:

To Alpha Centauri, the closest star to our sun.

4.3 Light Years

2,900 Years

To M3 a very large star cluster (we certainly could find other life forms there)

32 Thousand Light Years

21 Million Years

The far edge of the Milky Way

60 Thousand Light Years

41 Million Years

It is just not possible.


Thoughts on Traveling to the stars: I don't believe that we can send colonies of humans to the stars. In such a journey the people might reproduce over generations as the star-ship makes its way over time. Such a journey is too long and it is simply too dangerous for human anatomy, in my opinion. But there would be a way to package and preserve pre-harvested human eggs and human sperm. Machines could be constructed to protect the cargo until arrival then create human beings through in vitro fertilization. Other machines would nurture, educate and grow the new infants in orbit around some planet, New Earth. Humanity's children would be the offspring of our technologies.


To Other Galaxies


The problems now just get out of hand and it is not even worth making travel reservations.  The Sombrero Galaxy (M104) is a place that I would like to visit.  It makes a great picture after all.  It is 64 Million Light Years away (we have gone up from Thousands to Millions of Light Years).  This would multiply by 1,000 the number of years needed to travel even using our 1 Million MPH rocket.  That would take about 42,000,000,000 years.  We started measuring our calendars when; 2,000 BC years or so?  So this trip would take roughly 10,000,000 times longer than all of recorded human history on a rocket that is so fast that we do not know how to think about building it. (see an idea on speed-hitch-hiking). What makes this all worse is these estimates assume a static, non-expanding, universe. Of course the real universe is rapidly expanding and the expansion is increasing. In some distant day, no galaxies will even be visible through even the largest telescopes, so trying to travel to a galaxy that is running away is just not going to happen. In fact just going fast and faster is not really going to work either without some very exotic physics.


Andromeda, the closest major galaxy to us

2.3 Million Light Years

1.5 Billion Years

M104 Sombrero galaxy

64 Million Light Years

42 Billion Years



Deep Space


Pretty pictures, but you just can’t get there from here.  We are talking only 3 Billion Light Years for the objects that I can see in my telescope.  Hubble can see over 13 Billion Light Years. Until we can find a place or circumstance where the formula (Distance=Speed*Time) is no longer valid, it is just not doable.  I think that I will remove ET from my list of things to worry about.


Traveling at the speed of light: If we are able to increase the speed of travel, of course we can reduce the excessive time required for interstellar space travel. There is at lease some new theoretical work being developed in this area, and I refer you to the following article: http://www.msnbc.msn.com/id/31665236/ns/technology_and_science-innovation/ I believe that the mass of any object approaching the speed of light is supposed to approach infinity. This would not be good, and it is still hard for me to fully get behind this idea of light speed space travel.


Just a side thought:  I can photograph at roughly 3/13th (23%) of the distance of the Hubble Space Telescope, yet I spent an amount which is insignificant in comparison to the money spent on the Hubble.  Funding for those last Light Years is certainly expensive.




October 12, 2005

Updated: July 08, 2009

Updated: Oct 10, 2013

Updated: July 30, 2017