Astrophysicists using the High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory in Mexico have detected the extended emission of high-energy gamma rays around two nearby middle-aged pulsars, generated by high-energy electrons and their antimatter counterpart, the positrons. The properties of the detected emission cast serious doubt on one possible origin for a mysterious excess of positrons near Earth. HAWC map for the region around Geminga (about...