Link to the Transit of Mercury

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.
Transit of Mercury 2016 May 9

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!


6 thoughts on “Link to the Transit of Mercury”

  1. Our Virginia weather has been cloudy / rainy / astro-impossible for about three weeks straight now, but through a short break in the clouds I was able to see the transit for a few minutes and share it with some of my work colleagues. Maybe our weather will be better in 2019 for the next one! If we don’t get a good look in 2019, we’ll have to wait until 2032 . . . The world’s worst transit image is here:

  2. San Francisco was mostly cloudy this morning, and I had failed to do any contingency planning or reconnaisance of an inland site with better weather prospects. So I mostly watched online feeds from Sky and Telescope and Slooh, and saw a bit of the transit through my own telescope from the back yard through occasional thin patches in the clouds. Third contact was clouded over, but I’m pretty sure I saw the very last few moments before fourth contact. Mercury is a trickster — now you see him, now you don’t.

    By the way, I was impressed by the Slooh program. In addition to astronomers they also featured a mthologist and a cultural historian. The host, Englishman Paul Cox, was engaged and cheerful throughout the seven and a half hour feed, despite needing to don a parka and fur hat in an unheated observatory dome.

  3. These transits could be considered a subset of annular eclipses of the sun.
    With an exceptionally thick annulus!

  4. The link works well for me and I’m glad to see you getting back into your astronomical stuff. We seemed to have missed any reports on the Eta Aquariids…. Northeast USA was rained and fogged out anyway. I’m excited to see clear skies for Monday morning.

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