We hear of the true awesomeness of experiencing a total solar eclipse, from the one that swept across the American West in 1878 to the one that drew crowds to the totality's path in the US in August 2017. And we'll also learn what it's like to take part in a winter solstice ritual from inside Ireland's ancient tomb at Newgrange. Plus, author and conservationist Terry Tempest Williams describes breathtaking moments in America's national parks, and why it's critical to protect them from the forces that divide Americans today.