As North Korea’s president pledges to “denuclearize” the Korean peninsula, an international team of scientists is publishing the most detailed view yet of the site of the country’s latest and largest underground nuclear test on Sept. 3, 2017. The new picture of how the explosion altered the mountain above the detonation highlights the importance of using satellite…

One of the rare and brief bursts of cosmic radio waves that have puzzled astronomers since they were first detected nearly 10 years ago has finally been tied to a source: an older dwarf galaxy more than 3 billion light years from Earth. Fast radio bursts, which flash for just a few milliseconds, created a stir…