How much mass makes a black hole? Astronomers challenge current theories - August 19 Astronomers have for the first time demonstrated that a magnetar -- an unusual type of neutron star -- was formed from a star with at least 40 times as much mass as the Sun. The result presents great challenges to current theories of how stars evolve, as a star as massive as this was expected to become a black hole, not a magnetar. This now raises a fundamental question: just how massive does a star really have to be to become a black hole?...Read More
NASA's Viking 1 mission, launched on Aug. 20, 1975, put a spacecraft into orbit around Mars and delivered the first successful lander to the Martian surface.
Astronomers use galactic magnifying lens to probe elusive dark energy - August 19 An international team of astronomers using gravitational lensing observations from the NASA/ESA Hubble Space Telescope has taken an important step forward in the quest to solve the riddle of dark energy, a phenomenon which mysteriously appears to power the universe's accelerating expansion....Read More
Cosmic accelerators discovered in our galaxy - August 18 Physicists have discovered evidence of"natural nuclear accelerators"at work in our Milky Way galaxy, based on an analysis of data from the world's largest cosmic ray detector....Read More
