BBC News-21 March 2013-Jonathan Amos

A map tracing the "oldest light" in the sky has been produced by Europe's Planck Surveyor satellite. Its pattern confirms the Big Bang theory for the origin of the Universe but subtle, unexpected details will require scientists to adjust some of their ideas.

A spectacular new map of the "oldest light" in the sky has just been released by the European Space Agency.

The United Nations General assembly has proclaimed March 21 the International Day of Forests. From 2013, the day will be observed each year to celebrate and raise awareness of the importance of forests and trees to all life on Earth.  

Find out how you can take part in the celebrations and help sustain the world’s forests here. 

AURORAS LOVE EQUINOXES: The seasons are changing. Today, March 20th, the sun is crossing cross the celestial equator heading north. This marks the beginning of spring in the northern hemisphere and autumn in the southern hemisphere. At this time of year, day and night are of nearly equal length, hence the name "equinox" (equal night).

For reasons researchers don't fully understand, auroras love equinoxes. During the weeks around the beginning of spring or fall, the slightest gust of solar wind can provoke bright lights around the poles. A potent CME impact at this time can produce an unforgettable display, like this one only a few days ago:

"I took this photo during the historic St. Patrick's Day geomagnetic storm of 2013," says Ben Hattenbach of Fairbanks, Alaska. "I'm still exhausted from the experience, during which the aurora was at or near peak strength for the entire night. It was just incredible in a way pictures cannot come close to conveying."