The More Common Kind of Transit

Transit of Mercury, eh? A few news sites were pumping up today’s transit as a “rare” celestial event, but something that occurs 13 or 14 times per century here on Earth doesn’t merit that adjective. The next one’s going to be in 2019, for crying out loud. A transit of Venus, now that’s rare in human terms.

Besides, Mercury’s annoyingly hard to spot in the sky under normal circumstances. Is it ever known to hang so bright in the morning or evening sky like Venus? Glimmer red-orange like Mars? Appear as a bright white dot late in the evening like Jupiter or even the dimmer Saturn? No, it hides in the glare of the Sun.

Even so, I might have taken my eclipse shades out — the ones I used during the transit of Venus, without harm to my retinas — and looked for it this morning, but for one thing here on my part of Earth: completely overcast skies. Ah, well. I’m glad that didn’t happen back in ’12 and I hope it doesn’t happen for the solar eclipse next year.

Curiosity observed a transit of Mercury on Mars about two years ago, the first time any kind of transit has been observed from anywhere other than Earth (by earthlings, I should add), and something I didn’t know until now. That should have been bigger news than today’s garden-variety transit. Also, should there be observers on Mars — people or machines — in 2084, a transit of Earth will be visible from that planet.

Here’s a take on the transit of Mercury I saw in Lileks, in the comments section of all places. Then again, his comments section tends to be a cut above the norm.