It might be the world’s most baffling tourist attraction: a roaring pit of fire the size of a soccer field sitting in a barren desert. The Darvaza crater, known as the “Gates to Hell,” lies deep in territory of the isolated Central Asian nation of Turkmenistan. The crater has been burning for decades. Over the years it has become a quirky draw for adventurous visitors and a puzzle for scientists and researchers. It has even been the backdrop for a self-promotional video by a Turkmen president. But now, the flames of the “Gates to Hell” appear to be going out. Infrared imaging data taken this year shows that the fires within the natural gas crater are on the decline. The intensity of heat from the flames has diminished by more than 75% over the last three years, according to an analysis by Capterio, a company that monitors natural gas flares. At a time when so many fires — both real and metaphorical — have raged worldwide, this should have been entirely good news.…