INFLUENCE OF COSMIC RAYS ON EARTH'S CLIMATE. Do small changes in solar activity translate into climate change on our planet? One possible linkage is the sun's influence over the local flux of galactic cosmic rays (GCR); as the solar magnetic field gets stronger, fewer cosmic rays are able to penetrate to the inner solar system and Earth. And because the GCR are the biggest ionizer of air molecules in the lower atmosphere, they might play a role in processes like cloud formation. Henrik Svensmark, a physicist now at the Danish Research Institute (011-45-3-536-2475, hsv@dsri.dk), has studied the connection between GCR flux, solar activity, and climate on Earth. He finds that during the past 11-year solar cycle, Earth's cloud cover was more closely correlated with the GCR flux than with other solar activity parameters, such as solar radiance, the main energy emitted by the sun. Svensmark concludes that climate seems to be influenced by solar activity via the GCR-cloud connection. In other words, climate is partly affected by processes in deep space. (H. Svensmark, Physical Review Letters, 30 November 1998; see figure at Physics News Graphics.)