It went largely uncovered by the mainstream press, but NASA held a news conference last week to discuss the strange behavior of our source of light and heat. First the sun is blank – no sunspots. Every 11 years the sun goes through a sunspot cycle where we go from many sunspots (up to 100) to very few.  Sunspots have been recorded fairly accurately since the mid 1700s. However, no one forecast the sun to be this empty of sunspots for a couple of years. Also the strength of the solar wind (a stream of charged particles moving through space at a million miles an hour) has diminished by 20% since the mid-1990s and the speed of the solar wind has decreased by 3%. The solar wind is also 13% cooler than in the mid-1990s. The sun’s magnetic field has decreased by as much as 36% in that time. Solar luminosity is lower during periods of minimal sunspot activity and many scientists believe that prolonged periods of minimal sunspot activity lead to a cooling of the Earth, as seen in the Maunder Minimum in the 1600s (the Little Ice Age) and the Dalton Minimum in the 1800s. We have just come through a time of relatively high sunspot activity called the Modern Maximum, which coincided with an increase in global temperature from the 1980s to the present. It’ll be interesting to see if sunspot activity increases significantly in 2009. (image from SOHO)