Time and Distance

August 13, 2007

At our public night last Saturday (the 11th) we showed off various objects to the people in attendance, from Jupiter all the way out to deep sky objects like the Dumbbell nebula and the M13 star cluster. In our standard introduction to these objects, we give information like type, distance, and other interesting things. With deep sky objects, because we are talking immense distances of light years, we explain what a light year is. For instance, the distance to the Dumbbell nebula is approximately 1300 light years from Earth. That means it takes light from the objects 1300 years to get to our eyes. For some of these objects, by the time the light arrives on earth, they might not even exist anymore. It certainly boggles the mind.

Here are some common times for light travel to certain objects (using average distance between objects):

Earth to Sun — 8.3 light minutes
Earth to Moon — 1.28 light seconds
Earth to Mars — 4.3 light minutes
Earth to Jupiter — 35 light minutes
Earth to Saturn — 70 light minutes
Earth to Uranus — 2.5 light hours
Earth to Neptune — 4 light hours
Earth to Pluto — 5.33 light hours
Earth to nearest star (Proxima Centauri) — 4.3 light-years
Earth to Andromeda Galaxy (farthest object you can see with the unaided eye) — 2.9 million light years

As you can see, it takes a while to get places when you are in space. Unfortunately we don’t have warp drive, hyper drive, or anything else that exists in the minds of science-fiction writers (which is too bad). Space is vast.

Or like the quote from the book Hitchhiker’s Guide to the Galaxy: “Space is big. Really big. You just won’t believe how vastly hugely mindboggingly big it is. I mean you may think it’s a long way down the road to the chemist, but that’s just peanuts to space.”

So the next time you are outside under the stars, look up and consider what is out there, and how long it took the light from those objects to get to your eyes.

Oh yeah.. don’t forget to realize how beautiful it all is.