BREAKING: Charter bus overturns returning students to Virginia Tech, Radford

NASA TIME-LAPSE: The X-Ray Sun over 5.5 years

GREENBELT, Md. (NASA) - Behold five and a half years worth of full-sun observations from XRT. A dramatic illustration of the solar cycle, this movie begins about one year before the first reversed-polarity sunspot ushered in the current cycle on January 8, 2008. The solar cycle is a periodic variation in the Sun's activity that is caused by the gradual 'tangling' and eventual reversal of its magnetic field.


Get every new post delivered to your Inbox.

Join 5,659 other followers