The Forefront of Space Science : The 4.6-Billion-Year History of the Sun

There is a view that the Sun is in an abnormal state as evidenced by, for example, the lengthening of its usual 11-year activity cycle. But is this really true? This article considers the relationship between the Sun`s 4.6-billion-year history and the earth environment including the birth of life. Deepening our understanding of solar activity could also contribute to the solution to earth`s environmental problems.