The June Flowers of 2004

Abstract

By 2004, so many years had passed since the last transit of Venus that no witness of the previous event remained. Much had changed in the 122 intervening years. Once the incentive for launching worldwide expeditions, transits of Venus had long since been superseded as a means of measuring the solar parallax and determining the value of the astronomical unit. On the other hand, the 2004 event was used to model the dimming of distant stars as planets transited their disks, an application that would have seemed far-fetched at the transit of Venus in 1882. Also, twenty-first century observing techniques and methods helped solve two mysteries raised by the earlier observers—the basis of the infamous black-drop effect and the nature of the mysterious aureole or “ring of light.” The 2004 transit was even recorded from space—a triumph of technology that would have been unimaginable to scientists of the Victorian era, whose idea of technological feats included the laying down of the trans-Atlantic telegraph cable and the recent invention of the telephone. In 1874 and 1882, accounts of transit observations could be transmitted around the globe in a matter of days, while by 2004 communications facilitated by satellites in geosynchronous orbits allowed millions, linked to television and the Internet, to see Venus cross the Sun in real time—even if one were clouded out, or on the other side of the world. It was no longer necessary even to peek outside; the event could be witnessed in its entirety without ever leaving the comfort of one’s living room, though we would argue that this was not the most satisfying way of taking in an event that would be witnessed, at most, once more in the lifetimes of those living.