THE organisers of Europe's largest science event are ditching drab lab coats for fizzing test tubes of sexed-up shows.
Royal Observatory staff will deliver a lecture entitled X-Rated Stories In The Stars as part of the Edinburgh International Science Festival (EISF).
The strictly 18-plus event will reveal the salacious reality behind the naming of constellations.
Already a sell-out, the talk is part of a programme of adults-only events taking place at the Festival.
Others include author Paul Martin's presentation on the science of hedonism, titled Sex, Drugs And Chocolate.
Observatory staff routinely give children's talks about Greek mythology and the stars, but have decided to run a desensitised, grown-up version.
Education officer Tania Johnston said: "When we do the kids' talks we tell them versions of the Greek myths relating to the constellations.
"However, the real stories are far too raunchy and gory for young audiences.
"We thought it would be fun to do an adults-only lecture.
Most people are vaguely familiar with the myths from childhood, but have no idea about the torrid affairs and sordid behaviour that surround them."
The talk will outline how Ursa Major or the Great Bear came from one of Zeus's lovers, Callisto, being transformed into ursine form after their affair.
It will also touch on the lurid tale behind Orion.
Johnston said: "Orion is one of the constellations that people recognise the most, but they more than likely won't be aware of the background.
"In one version of the story a lady, Artemis, fell in with Orion and her brother Apollo grew jealous because there was a little bit of a strange brother and sister relationship going on there. He basically ended up getting Artemis to kill Orion without her knowing.
"Apollo persuaded Orion to swim out as far into the lake as he could and persuaded his sister to aim for the black dot in the distance with her bow and arrow – Orion, of course."
The talk will also focus on the graphic violence which is central to many of the legends.
"There is quite a lot of blood, guts and nastiness in the stories. For example, in the children's versions we really have to tone down the idea that Queen Cassiopeia decided to sacrifice her daughter to the sea monster Cetus."
Ian Ridpath, broadcaster and editor of the Oxford Dictionary of Astronomy, said ancient mythology was not for the faint-hearted.
He said: "Real stories contain graphic accounts of everything from rape and buggery to bestiality."
"The Greek god Zeus was undoubtedly the greatest kiss-and-tell lover in history.
"Not only did he try it on with anyone who took his fancy, female or male, but boasted about it in the most public way possible by commemorating his conquests in the form of constellations in the sky."
The £8-a-head lecture, which includes a glass of wine, will take place at the City Art Centre on Thursday evening.
