May 4, 2012

EARTH: North Star Loses Mass But Still Shines Bright

The North Star, the Pole Star, the Guiding Star, Polaris: Its many names reflect the many centuries humans have gazed northward to it for guidance. However, recent studies have shown that the North Star is losing mass at a significant rate. Will Polaris, steadfast beacon for early sailors and adventurers alike, vanish from the night sky?

Hilding Neilson of the Argelander Institute of Astronomy at the University of Bonn in Germany thinks that he and his colleagues have unlocked the answer to the North Star's decreasing mass. Although the North Star's peculiar alignment with the Earth's North Pole makes it seem motionless, the North Star actually pulsates, varying daily in size and luminosity. Neilson and his colleagues say that the lengthening of these pulses may hold the key to Polaris's enhanced mass loss. Why? Read more and find out online at

Check out this story and more in the May issue of EARTH Magazine, available online now at Shed some light on life-bearing planets with Earthshine; determine whether M.Y. is an abbreviation or a unit of time; and, travel to Santorini, Greece, all in this month's issue of EARTH.


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