May 9th through 15th marks International Astronomy Week this year, with Saturday the 14th designated as official Astronomy Day. This is the time of the year astronomy groups use to bring their hobby to the public through various organized events.
Unfortunately, I am neither a group nor organized; the most exciting thing I currently have scheduled is a dental appointment on the 13th in Regina, but that’s just for me. It appears the universe stops for no one, not even periodontists.
Astronomy Week does, however, start off in style. A couple of weeks ago, Mercury could be seen setting shortly after sunset. On the 9th, it can again be spotted, only this time crossing the face of the Sun. The innermost planet of our solar system, Mercury transits are semi rare events which occur at a rate of thirteen or fourteen a century, anywhere from three to thirteen years apart in a regular pattern only a mathematician could appreciate (or explain). The last ones were in 1999, 2003 and 2006, and the next will be in 2019, 2032 and 2039.
On the 9th, the transit gets an early start, beginning at 5:12am, five minutes after sunrise; it will end 7-1/2 hours later at about 12:44pm. Unlike a lunar eclipse where things happen quickly, this Mercury transit will be a lengthy, tranquil event.
Unfortunately, as with anything involving the Sun, planetary transits are not something you just walk out and see.
During the transit, Mercury will appear as a tiny black dot moving slowly east to west across the Sun. The smallest of the planets (now that Pluto has been unceremoniously dumped), Mercury is less than half the size of the Earth. Jupiter and Saturn have moons that are bigger. I say this not to ridicule what is otherwise a pretty nice planet, but only to emphasize that it’s small. In front of the Sun, it’s downright tiny, a mere dot 158 times smaller than the solar disk. It will take a telescope to see it.
Looking at the Sun with a telescope is a mistake you make only once, so DO NOT TRY THIS AT HOME. I’m mentioning the transit only because the fact it’s happening is interesting; the event itself is not spectacular enough to be attempted casually because of the risk to your vision involved.
Weather permitting, I will have a properly filtered telescope in my driveway at some point that morning. Another time, perhaps I can be more organized and invite you as well, but in reality, you will have better (and safer) views via news coverage or by searching the internet.
So, for your information only, be it known that there will be a transit of Mercury, sunrise through the noon hour on May 9th, NOT available from your own back yard.
