A Pinkie

16 Sep 2017

A pink aurora over Yellowknife in the North West Territories of Canada ...

   ... taken by Yakchi Takasaka (see www.spaceweather.com Sept 15th). The pink colour is probably a sign of nitrogen. Most auroras are green - caused by energetic particles hitting oxygen atoms in the high atmosphere. Pink aurora occur as particles descend lower than usual striking nitrogen molecules.

Meanwhile, at https://phys.org/print424600861.html ... astronomers are looking into the origin of Planet 9 (given a less exotic location), while at https://phys.org/print424874419.html ... we have a new theory on the origin of the asteroid belt. Finally, at https://phys.org/print424605717.html .... researchers at the University of York have shown that molecules reaching Eath via meteorites could potentially be  ancestral to the building blocks of DNA.