See the Meridian laser

The evenings are already starting to lengthen, making it much more likely that we all find ourselves wandering around outside after dark. If doing so in a particular part of South East London, a green laser is often seen in the sky over the Thames and Greenwich, marking the Prime Meridian of the World – Longitude 0º.


A laser has been shining out from the Royal Observatory since 1993, and the current version has been doing so since 1999, when a more effective Millennia VS Diode-Pumped laser was installed.

For more, see http://www.thegreenwichmeridian.org/tgm/articles.php?article=14


_{^Picture © Toms Bauģis used under a Creative Commons license^}