On Monday May 9 comes the passage of the pinpoint black planet (here shown 5 times larger than scale) across the vast boiling face of the Sun.
It starts around dawn as seen from eastern North America, around noon by the clock for Europe. It has to count as one of the year’s special sky events, since it last happened ten years ago, though it’s not as rare or grand as a transit of Venus, and is not observable without a telescope and special precautions.
There is a whole page on it in my Astronomical Calendar 2016. And so it occurs to me that instead of picking some aspect of it to talk about I could make that page available to you. A PDF of it should open if you click on this:
You might pay attention first to the paragraph near the end that starts: “DON’T BE BLINDED.”
Even if you have the book, an advantage of seeing it on the screen is that you can enlarge it , and thus see the illustrations at any magnification.
So this is a blogging experiment for me. Let me know if it doesn’t work for you.
There is of course much about the transit in the May issue of Sky & Telescope: two pages by Alan MacRobert with his usual mastery of everything observational. There is also an article by Thomas Dobbins on strange effects noticed at earlier transits, especially a wide bright ring that some skilled observers were sure they saw around Mercury – as wide as a third of Mercury’s radius, and brighter than the Sun’s surface in the background. This is emphatically shown in a 1960 Nov. 7 image which V.A. Firsoff made by projection onto white cardboard. The caption should, but does not, add that this image must be a drawing, not a photograph – since the consensus now is that this phenomenon was an optical illusion. I even thought of writing a carping letter to S&T about this little lapse; but I don’t have to, since I can carp about it here!