Thanks to some excellent advice from Neville Young, in his new book Astronomy within Reach, we can all amaze and astound our friends by helping them to see the planet Venus with the naked eye, in full daylight. Regular readers will have already seen photographs showing that such a thing is possible, and should have worked out that Venus is bright enough to show up well against the blue daytime sky. The problem is that the human eye has an autofocus feature which is really hard to override, and if there is nothing clear to focus on then it defaults to a distance of only a few meters. Even if you happen to be looking at the exact spot in the sky, your eye cannot resolve the tiny white pinprick of Venus when it’s so far out of focus, and so it remains invisible.
Fortunately, Venus often passes near the Moon, and if you know when these conjunctions will occur, you can use the moon to get focus, and then let your gaze drift a degree or two in the right direction to spot Venus as clear as, well, daylight! There are a few such times coming up for the rest of 2012: 13 and 14 August, 12 September, 12 October and 11 November. For more details on when and where to look, and what makes those particular dates better than other conjunctions, visit Neville’s webpage at http://www.starwaders.com.