Comments on: How many time magnification does a telescope have to be in order for me to view Pluto?

By: Tom A

Tom A — Mon, 05 Oct 2009 19:56:42 +0000

The guy who discovered Pluto was looking through a huge instrument. The only way he could see it was by looking at two photos of the sky taken through the scope several nights apart. He looked through a viewfinder and changed repeatedly from one photo to the other. Eventually, he noticed that one of the tiny points of light was in a different place on the two photos.

That’s how it will look through any scope capable of seeing it. Ten inches aperture at least, and even if you can get a computer to find it, it will be difficult to see exactly which of the tiny dots it is. Tom A

By: Geoff G

Geoff G — Sat, 03 Oct 2009 07:25:53 +0000

As others have said, magnification is not the relevant factor in seeing Pluto; aperture is. I myself have seen Pluto several times with telescopes of 10″ and 11″ aperture, but Pluto is currently moving away from the Earth, so is increasingly difficult to see. Again, as others have said, all you will see is a pinpoint of light, indistinguishable from a 14th magnitude star, except that it moves a tiny bit from night to night. I used around 200x to observe Pluto.

A 10″ Dobsonian telescope similar to the one I used will cost you around $500 to $600, but you will probably require a couple of years experience using it in order to locate and observe a difficult object like Pluto. Geoff G

By: nick s

nick s — Fri, 02 Oct 2009 17:52:07 +0000

As described above, magnification means nothing when looking at Pluto and the stars.

Stars look like points of light in any telescope, and Pluto is small enough and far enough away to always present just a point of light.

The light-gathering ability of the telescope is what you need consider. Your eye pupil is only about 10 mm, so its light gathering is tiny.

That is why 50 mm binoculars show thousands more stars - 5 times your pupil width means 25 times the light -gathering (you will see things that are 25 times dimmer than with the naked eye).

So, imagine a 10 inch telescope - that is 250 mm - it gathers 25 x 25 = 625 times as much light as the naked eye.

That is the least you will need for pluto. But even then, you will be disappointed. nick s

By: Reginald

Reginald — Fri, 02 Oct 2009 05:01:52 +0000

It isn’t the magnification, but rather the light-gathering ability
of a telescope that enables you to see distant objects. You
need a telescope of sufficient aperture, or diameter of its
objective lens or mirror, that will gather enough light for Pluto
to be visible. A telescope of at least 10-inch diameter might
show Pluto, but it will just appear as a faint speck in ANY
scope, even the Palomar giant! Reginald

By: skymaster

skymaster — Thu, 01 Oct 2009 03:03:28 +0000

No chance, at magnitude 14.5 you would need a telescope of at least 10 inches and even then it would look like a tiny speck.

Seems to me you are thinking of using one of those wretched department store telescopes made of plastic. Be warned-it will put you off for life.

A half decent 10 inch SCT eg (Meade) would cost you at least US$5000 a good one like a Takahashi Mewlon probably nearer $10,000 with all accessories. skymaster

By: Dan

Dan — Mon, 28 Sep 2009 19:51:53 +0000

Unfortunately any telescope that you can afford is still going to leave Pluto looking like a speck against the night sky.

Don’t take that the wrong way, just that even the best telescopes created by man can barely image it.

At it’s closest approach to the Sun, it is over 2 Billion miles away, and is very tiny. Dan