About 13 times per century, the planets align in the heavens and the Earth can watch Mercury crossing the face of the Sun. NASA's Solar Dynamics Observatory was watching too and captured time lapse videos from several angles using various instruments measuring magnetism, visible light, and UV. The cosmic ballet goes on.
kottke.org posts about mercury
Water in Mercury's atmosphere Jul 07 2008
Scientists were recently "astonished" to find water in Mercury's atmosphere. Plus, the particles in the atmosphere were blasted off the surface by the solar wind so the atmospheric water could indicate that it can be found on the surface as well. First Mars and now this. Has The Onion done a "Scientists find evidence of water on Earth" story yet?