Shades of the goddess: Venus in transit

I review the talks given during IAU Colloquium 196, sometimes in a revised order to suggest certain connexions. The AU now, its definition, value and uncertainty, and its modern determination are contrasted with the situation in 1640. While there are differences, not least in the value of the AU and its error, some things have not changed. As an enduring constant we require: a correct theoretical framework, precise observations, and accurate calculations. The history and context of Horrocks' transit observations are set against the backdrop of our own sightings during the 2004 event, and our journeys to Carr House and other sites in Much Hoole.