Scientists have observed the biggest supernova – stellar explosion – ever detected, the violent death of a huge star up to 100 times more massive than our sun in a faraway galaxy.The supernova, releasing twice as much energy as any other stellar explosion observed to date, occurred about 4.6 billion light years from Earth in a relatively small galaxy, scientists said. A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).It might represent, they added, a type of supernova that until now has …

Dr. Anthony Fauci, the government’s top infectious disease expert, said Tuesday the U.S. does not yet have the critical testing and tracing procedures needed to begin reopening the nation’s economy, adding a dose of caution to increasingly optimistic projections from the White House.   “We have to have something in place that is efficient and that we can rely on, and we’re not there yet,” Fauci said in an interview with The Associated Press.   Fauci’s comments come as President Donald Trump and others in the administration weigh how quickly …

The WHO said its emergency committee would meet Tuesday to discuss whether the Ebola outbreak in the Democratic Republic of the Congo still constitutes an international health emergency, after fresh cases were detected.   The meeting comes a day after DR Congo had been expected to announce that the outbreak in the east of the country that began in August 2018 was over.   The epidemic has killed 2,276 people to date. For it to be declared over, there have to be no new cases reported for 42 days — …