La Palma has a lovely sub-tropical climate. It’s called the land of eternal spring. But today the top of the mountain is covered with snow. Of course, we only ever get snow at high altitude, and these days, we don’t get snow every winter. But when it snows, it can dump several feet in one night. The Roque is one of the three best sites in the world for…
Twinkling stars are pretty, but astronomers would much rather they didn’t. The twinkle is caused by movement in the air above you (the same as a mirage on very hot days) and it stops the astronomers getting a clear view. The Hubble Telescope gets such wonderfully clear images because it’s out of the atmosphere altogether. But there’s only one Hubble, and it cost a fortune. So they build ground-based…