Dr. Katherine Volk

You can go online and Google blink comparator, and there's a thing that will mimic it.

It made me motion sick really fast.

I couldn't do that.

This kind of discovery by photographic place doesn't work very well for distant objects in the outer solar system.

There's a few things going against us.

They're farther from the sun, so they have slower orbital velocities.

So just by themselves, they're not moving very fast around the sun.

They're much farther from us, so the effect of parallax as we are moving in our orbit is much smaller than for the asteroids.

and they're also so far away that they're extremely faint compared to asteroids and other things that are nearby because you get penalized twice for the distance because you have to have the light dropping off as it gets out to the Kuiper Belt and dropping off as it comes back to the Earth so it's really a different story now of course there was you know spinning beach ball that's nice so there were some objects in the outer solar system discovered

by photographic plate and blink comparator.

Of course, the most famous one is Pluto in 1930.

And that blink comparator in the earlier images was the one Clyde Tombaugh used.

And these are copies of those photographic plates.

There's Pluto on January 23.

There it's moved on January 29.

If those arrows were there, I would never have spotted that.

But it can work.

But what we usually do now with CCDs is we take a bunch of images of the sky, and we run the images through a search algorithm.

And the computer picks out the things that are not stationary in the images.

Now, it still involves a human looking at every candidate for Kuiper Belt stuff.