BOSTON GLOBE: The Sun is now in the quietest phase of its 11-year activity cycle, the solar minimum — in fact, it has been unusually quiet this year — with over 200 days so far with no observed sunspots. The solar wind has also dropped to its lowest levels in 50 years. Scientists are unsure of the significance of this unusual calm, but are continually monitoring our closest star with an array of telescopes and satellites. Seen below are some recent images of the Sun in more active times. MORE
EDITOR’S NOTE: HIGHLY RECOMMENDED
FACTS: The Sun is about 4.5 billion years old. Since its birth it has used up about half of the hydrogen in its core. It will continue to radiate “peacefully” for another 5 billion years or so (although its luminosity will approximately double in that time). But eventually it will run out of hydrogen fuel. It will then be forced into radical changes which, though commonplace by stellar standards, will result in the total destruction of the Earth. MORE