Where to Put the Thousand Mile Telescope

But where can we put this monster?

Siting the Thousand-Mile Telescope is probably going to be non-trivial.  We can't just find some wasteland that nobody cares about -- for example New Jersey -- and cover that up.  The telescope is too big.  It has a surface area a little larger than Mexico.

And there are all kinds of problems even more serious if we locate dishes on the Earth's surface -- like gravity, wind, vast and immediate climate changes, disruption of the lithosphere with massive strip-mining to get the materials.  We would probably cause the deaths of a couple billion people, which seems likely to make the instrument unpopular with the survivors.  So -- not on the Earth.

Problems Likely at This Location

No, our dish-arrays really can't even be on the moon.  Still too much gravity to be able to maintain such large paraboloids -- which will also have to be extremely thin to avoid using inconceivable quantities of material.  Such big thin things would flatten out like a coat of spray-paint even in lunar gravity.

Getting colder, but still not cold enough.

No, it has to be in zero G.

But then that brings up another couple of problems.  First -- where are we going to get all this material?  Even with the disks being very thin, a thousand-mile disk uses a lot of mass.  If we have to boost it up out of a strong gravity well, we are doomed.

And second -- if we build them anywhere near the Sun -- well, we will basically be building the biggest sails in the history of the human species, and the wind from the sun will blow them away like little soap bubbles on a breeze.  We do not want to make these things just so we can watch them receding into the infinite distance.

No, we need a place where:

• We can get lots of material with practically no gravity.
• It's far enough from the Sun that light pressure is negligible.

As it happens -- I have just the place!  But we will need to zoom back a ways.

The size of the Sun in this picture, by the way, is to scale with the size of the orbits.  The Sun is very big, very powerful, very calm, very special.  Anybody who tells you that the Sun is an 'average star' has no faintest clue what they are talking about.

We need to get out past the orbit of the Earth, only 500 light-seconds away, where the intensity of Solar radiation is nearly a Kilowatt per square yard.

We need to keep going, out beyond Mars.

We might pause and think about the asteroids for a bit, but the sunlight is still too intense, and Jupiter keeps sweeping by cheerfully disrupting everything, throwing his big gravity field around and hurling hundred-mile lightning bolts in all directions.  It's like having a neighbor who plays loud music all night.

No, we have to get well away from mighty Jupiter.  There is a better place, but it's still far away.  Keep going out, while the light-minutes turn to light-hours.

Out past ringed Saturn and Uranus.

Look, I know it's going to be hard to get people to come out this far, but a lot of the work can be automated, and anyway there will always be astronomy grad students.


We keep going past the orbit of Neptune, the final planet we know about ...

Until at last we see it.  Five light hours from the Sun, the real asteroid belt of the Solar System -- the vast Kuiper Belt.

The Kuiper belt has zillions of little rocks and ice-balls, some of them ranging in size all the way up to that of Pluto.  In fact, Pluto is probably just a large and close-in Kuiper Belt object.  The belt has a total mass of 5% of the Earth or so -- which is a very great deal of mass which we will be very happy to get our hands on -- spread out over an area of four thousand square AUs -- 40 million trillion square miles.  So it's spread kind of thin.  But that's OK, we will find some decent-size chunks and go use those.


And specifically, we will go to a magical little band of the Kuiper Belt -- well, 'little' meaning only 100 million miles wide --

The 'Kuiper Cliff' -- a band where there are very few floating things, but which is right next to regions that are nice and thick with material we can use.

Here, we are 40 times farther from the Sun than is the Earth.  Solar radiation is 1600 times weaker.  Even on our gossamer dishes such weak wind will do next to nothing.

It's cold, it's dark, it's lonely.  Nobody who didn't already know exactly where to look would be able to find our little dishes in a million years.

It's perfect.