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Discussion: Transit of Mercury

in: ken; ken > 2019-11-10

Nov 11, 2019 3:07 AM # 
Seems like I saw you had a small newtonian reflector telescope at one of the Wallops launches. If so, that will be great for watching the transit of Mercury tomorrow. Just use eyepiece projection - use a white card and project the image onto it. You can point the telescope by looking at the shadow - don't try to sight by looking along the tube at the sun! Also if you have a spotting scope on the side be sure to keep it capped to avoid accidentally looking through it.

Here are some pics of eyepiece projection through my own scope during the 2017 eclipse:


In the last one you can see that I used a cardboard box with a hole in it to stop down the aperture, but with a small open-tube newtonian you shouldn't need to do that unless you want to. If you do, be sure to put the hole off to the side rather than in the center. *NEVER* look through the scope, even with it stopped down! Always project and only look at the projected image on a card. In that pic you can also see a pair of binoculars stopped down the same way and used for projection. I've done this for a Venus transit through my office window at work. Mercury will be a much smaller dot than Venus though. You might even be able to see some sunspots. The whole transit takes ~5 hrs, so its no rush unless you want to see it right on the limb. Try marking its location on the projection every 15 mins or so to make a track.
Nov 11, 2019 12:19 PM # 
Looks like clouds today, might have to watch here:

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