Celebrate Sun-Earth Day on March 18th by reading this very accessible and beautiful book by Tufts University Astronomy Professor Kenneth R. Lang. (Science teachers if you're not already familiar with Sun-Earth Day, check out NASA's website at sunearth.gsfc.nasa.gov. The theme this year is 'Live from the Aurora').
A relatively small-scale transient event on our Sun could mean life or death on Earth. "Sun, Earth and Sky" will teach you about sunspots, solar flares, and coronal mass ejections: chunks of the Sun's outer atmosphere that blow off into space and can strike the Earth, causing aurorae and disrupting power grids and satellite communications. We humans actually live within the Sun's atmosphere, so it should come as no surprise that this medium-size star plays a dominant role in our lives. One of this book's main themes, as can be guessed from its title, is the interaction between the Sun and the Earth's atmosphere through radiation and high-energy particles.
As with all astronomy texts, "Sun, Earth and Sky" went out-of-date immediately after publication in 1995 and does not contain recent discoveries such as solar tornadoes (first imaged by SOHO in 1998), the Solar Max 2000 research, or the data from RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) space probe, launched in early 2002. However, that's no excuse not to read this book. I originally bought it to learn more about the interaction between solar flares and the Earth's magnetosphere (very lucidly explained), but soon found myself leafing through it just to look at the beautiful pictures (133 including 61 in color).
Dr. Lang starts out by describing the Sun as a cosmic laboratory--a site to test physical theories under conditions not readily attainable on Earth. He proceeds painlessly, i.e. without too much math or nuclear physics, to describe the inner Sun, "an unseen world of perpetual change and cosmic violence." Along with more standard illustrations, he also includes paintings by Turner and Monet. His chapters on the violent, visible solar phenomena such as CME (coronal mass ejections) are among the most interesting in the book.
And who would have guessed that we haven't yet solved the puzzle of the Sun's million-degree corona, even though its temperature has been known since the late nineteenth century.
As Dr. Lang approaches Earth he drills down into such topics as our planet's magnetosphere, our atmosphere and its vanishing ozone, and the effect that an 'inconstant sun' has on our well-being--indeed, on our very survival as a species.
I highly recommend "Sun, Earth and Sky" to anyone who is interested in a thorough grounding in solar astronomy.
For completely up-to-date information on our Sun, check out the soho[...] There are some great pictures courtesy of the Solar and Heliospheric Observatory (SOHO). You can even download a SOHO real-time solar images screen saver as part of your Sun-Earth Day celebration.