In this photo taken Wednesday, May 6, 2015, shoppers browse at a store in the Bayside Marketplace in downtown Miami. The Commerce Department releases retail sales data for April on Wednesday, May 13, 2015. (AP Photo/Alan Diaz)

US retail sales flat-line in April

U.S. shoppers kept their spending in check in April, as modest wage growth over the past year keeps family budgets tight.

Petro_Europa's Surface NASA gov_May12

Space mystery may be as simple as salt

NASA researchers have recreated a chemical substance found on one of Jupiter’s moons in laboratory testing; the “mystery material” may sugge…