Friday 9 October 2009

Don't look back into the sun

This week I've started looking for sunspots. You musn't look at the sun directly. You'll seriously damage your retina. To look at it, block off one side of the binoculars and shine the sunlight through the other side onto a piece of paper. The second picture shows the image of the sun thus obtained. Sunspots are slightly colder areas on the surface of the sun. There are none in view at the moment. The sun rotates on its axis every 25 days. Maybe in a couple of weeks ...
Sunspot activity goes in 11 year cycles. I thought it was supposed to be good at the moment, but maybe I've picked a bad time to start.