Moon safe for long-term human exploration, first surface radiation measurements show
Astronauts on the Apollo missions of the 1960s and ’70s carried dosimeters to measure their radiation exposure
Stellar explosion in Earth’s proximity
While a very close supernova could inflict massive harm to life on Earth, this one was far enough away
Scientists just worked out the total amount of matter in the universe
In total matter –the stuff from which humans & objects on Earth are made– makes up around a third of the total matter & energy in the universe
