Why we haven’t found another Earth. Yet. by Nola Taylor Redd The search for alien Earths is heating up. But there’s still no place like home. Mercury: Land of mystery and enchantment by Jesse Emspak With MESSENGER behind us and BepiColombo to come, planetary scientists seek to understand the puzzling innermost planet. Illustrated: What happens when stars collide by David Stevenson A cosmic star crash may light up the galaxy or be nearly undetectable. Target 25 treats in Leo by Michael E. Bakich Pull out your biggest scope, and the galaxies in this kingly constellation will dazzle you. Sharing the sky above Las Vegas by Raymond Shubinski This new observatory shows that what happens in Vegas also can inspire and educate. Stargazing in the city by Korey Haynes Dark sites are great for veteran observers, but when throwing a star party for new friends, go where the people are. 11 top winter binocular treats by Phil Harrington Star clusters, asterisms, double stars, and even a nebula beckon cold-weather skygazers. We test Nikon’s hot new astrocamera by Tony Hallas The D810A full-frame sensor produces colorful, ultra-low-noise images.