Temperatures have plunged to -30C (-22F) and below in parts of North America as extreme cold weather known as a polar vortex strikes the region ... in snow All images subject to copyright ...

The historic space voyage will last between three and five days, with the crew observing Earth’s polar regions from an altitude ... the first human X-ray images in space. Such research will ...

The vortex is essentially an area of low pressure in the upper layers of the atmosphere over the polar region up north. This vortex consists of powerful westerly winds in the stratosphere ...