Radio Astronomers Lift ‘Fog’ On Milky Way’s Dark Heart; Black Hole Fits Inside Earth’s Orbit

Thirty years after astronomers discovered the mysterious object at the exact center of our Milky Way Galaxy, an international team of scientists has finally succeeded in directly measuring the size of that object, which surrounds a black hole nearly four million times more massive than the Sun. This is the closest telescopic approach to a black hole so far and puts a major frontier of astrophysics within reach of future observations. The scientists used the National Science Foundation’s Very Long Baseline Array (VLBA) radio telescope to make the breakthrough.

New Fossil Links Four-legged Land Animals To Ancient Fish

Arlington, Va.—How land-living animals evolved from fish has long been a scientific puzzle. A key missing piece has been knowledge of how the fins of fish transformed into the arms and legs of our ancestors. In this week’s issue of the journal Science, paleontologists Neil Shubin and Michael Coates from the University of Chicago and Ted Daeschler from the Academy of Natural Sciences in Philadelphia, describe a remarkable fossil that bridges the gap between fish and amphibian and provides a glimpse of the structure and function changes from fin to limb.

Lightning Strikes and Rays Follow

MONTREAL, CANADA—Electrical storms can light up a midsummer night, but the dazzling forks are just part of the show. Invisible gamma rays shoot out of the sky minutes to hours after lightning strikes, researchers have learned. The team suspects that nuclear reactions fizzing in the atmosphere may be the source, and lightning could be the trigger.