The gaseous aroma that stank up NYC and parts of Jersey on Jan. 8 will remain a mystery. The offending odor, which lasted until approximately noon, covered Manhattan from the northern tip down to Greenwich Village and across the Hudson River to New Jersey, leading to some building evacuations and mass transit disruptions. But officials in both states say they’ve given up the search for the source. Sensors in New York found no chemical signature that would indicate what could have caused the problem and, likewise, nothing was explained when environmental investigators in New Jersey reviewed the records of more than 140 facilities. After Mayor Michael Bloomberg assured us the odor was not harmful, despite not knowing from whence it came, it’s not surprising that officials are content to abandon the search.