Tuesday night the sky will put on a once-in-a-lifetime
event. The planet Venus will cross the
face of the sun. The next time this will
happen will be in 2117.
The transit will start at 6:09pm EDT so the farther west in
the US you are, the better/longer you’ll be able to see it. The transit takes about 6 hours to complete,
so here in The Sticks we’ll only be able to see it to the halfway point.
It is really easy to watch but DO NOT LOOK DIRECTLY AT THE
SUN!!!!! (Yeah, I know you’ll have heard
that before but I have to say it again…).
To watch all you need to do is to build a “pinhole camera”. It is really, REALLY easy to do. Oh, by the way. The awesome thing about these pinhole cameras
is they really are “cameras” (so to speak).
What you look at is the true image of the sun… not just sunlight coming
thru. How cool is that?!
It can be done with a shoe box. HOWEVER, there is some sort of math ratio where
the greater the distance from the opening to the ‘screen’ (i.e. the length of
your box), the larger the projection will be.
And since you will want the image to be large, you will need some decent
length to your tube.
Himself had mailed home some old sea charts and I still have
the four-foot long boxes. I snatched up
one and in about 10 minutes had a rough pinhole camera!
On one end I sliced in a ‘viewing window’ and put a piece of
white paper at the end. This is where the
sun’s image will be projected. You can
see I just shoved the folded paper in and it still work well. Best would be to have it nice and flat.
At the other side I sliced off the whole end. Then I took a flat piece of cardboard and cut
it to the same size at the box end. In
the middle of that piece I cut a square about of about an inch and a half. I then taped a piece of heavy duty foil over
the hole and attached the piece to the end of the tube (thus recovering the end
like a cap).
Last step was to poke a hole in the very center with a pin.
Now it was time to look at the sun!
Finding the sun – without looking at it – is a bit
tricky. Here’s a tip to do it. Look at your shadow on the ground. If the pinhole camera looks like a tube… you’re
off. If it looks like a square (or
whatever the shape of your tube is)… you’ve just about got it! Having someone to help ‘aim’ makes it lot
easier.
Here’s my first view of the sun. Too much light was hitting the ‘screen’. You can see the image at the bottom of the
V.
Not good enough…
So I tried darkening the viewing area by putting a towel
over my head (think the old-time cameras where the photographer was behind a
cover).
MUCH better even tho there was still a bit of light bleeding
thru. (Sorry about the blur, not enough
hands to hold everything and get a steady photo!)
Himself came over and tucked up the towel around my camera
hand. Next time I’ll use a small blanket
to make it even darker and easier to work with.
And WOW… this is what I saw.
Folks… that is the sun’s corona you are seeing!! The astronomy sites I visited to learn about
this say that with a longer tube, you can actually watch sun spot activity.
So you know I was off to Lowes to buy a section of PVC pipe. Got one that is 10 feet long and 4 inches in
diameter. Himself cleaned the grime off
of it and is going to cut out my viewing area before Tuesday.
This is going to be SO fun!!!
note: Do not look at the mirror!
ReplyDeleteSome one used a small mirror as "pin hole" and projected onto a shady wall with paper or into a shaded room through the window. The farther the hole the bigger the image. The size of the mirror has to be adjusted just like the pin hole.
10 ft give 1 inch image
30 ft give 3 inches
50 ft gives 5 inches
100 ft give 10 inches