Did Betelgeuse burp?

Astronomers say they’ve solved the mystery of why Betelgeuse, a bright star in the Orion constellation, abruptly dimmed in late 2019 and early 2020. At the time there was speculation that the red supergiant, which is some 15 to 20 times more massive than the sun, was about to explode in a supernova. That would have been quite the light show: The last supernova in our galaxy that could be observed from Earth occurred in 1604 and was as bright as Venus in the sky. But a new study suggests the dimming was merely caused by an ejection of gas—a Betelgeuse burp. Detailed images of the star taken with the Very Large Telescope in Chile indicate the dimming was the result of two linked phenomena. A cool spot on Betelgeuse’s surface made the star appear less bright. And this cool spot was causing gas that had previously been ejected by the star to condense into dust—making things even dimmer. When the dust eventually settled, the star returned to its normal brightness. “I don’t think this event means Betelgeuse is going to go supernova anytime soon,” co-author Emily Cannon, from Katholieke Universiteit Leuven in Belgium, tells BBC.com. “Even though that would be incredibly interesting.”

mines: bacteria that glow in the presence of explosives. The process involves tweaking the genetic code of E.coli, reports The New York Times. First the researchers swapped in genes from bioluminescent marine bacteria that naturally emit light. They then trained the bacteria to light up in the presence of 2,4-dinitrotoluene, a chemical that leaks from TNT into the soil surrounding a land mine. Because the light is faint, the researchers also created a device that shields the bacteria and detects when it is glowing. Field tests conducted with the Israeli army have been “generally very successful,” says research leader Shimshon Belkin. The team’s hope is that these bacteria can eventually be dropped into minefields by drones, minimizing the need for humans to get close to the explosives. One challenge Belkin and his colleagues are still working on is temperature. The bacteria sensors work only between 59 and 99 degrees Fahrenheit, so they can’t be used in scorching desert conditions.

tional study of unprecedented size has concluded that the aging process is, sadly, unstoppable. The research, a collaboration of scientists from 14 countries, tested the “invariant rate of aging” hypothesis.

This holds that a species ages at a relatively fixed rate once it reaches adulthood. The researchers compared age-specific birth and death data from a diverse set of human populations—including peoples from the 17th to the 20th century—and from 30 nonhuman primate populations, including chimpanzees and monkeys. They found that the pattern of mortality was the same across the board: The risk of death is high in infancy, drops and remains low until early adulthood, then starts to rise again. That suggests humans are living longer not because they’re delaying the aging process, but because more and more people are surviving the high-risk period in infancy. “The trajectory towards death in old age has not changed,” coauthor José Manuel Aburto, from Oxford University, tells The Guardian (U.K.). “Evolutionary biology trumps everything and, so far, medical advances have been unable to beat these biological constraints.”