According to that, the capsule will be opened in 2108. So what's the relevance of burying it in the stonehenge landscape? It is just absurd. Besides, come 2108 people will be just cursing us for having made such a selfish mess of the planet, they won't want to read some inane text-message style comment from those freaks in the past. Well I doubt it anyway. Also one would hope they'd be more interested in archaeology connected with the stonehenge from prehistory, not the coke bottle tossing tourists of the 21st century.