Three months after announcing the first detection of gravitational waves, scientists report a second observation of the merger of two black holes made on 26 December 2015. The scientists were able to infer that the mass of the black holes was between 8 and 14 solar masses and the event took place at a distance of about 1.4 billion light-years from Earth.
The Earth’s magnetic field is produced by the geodynamo, the rapid motion of huge quantities of liquid iron alloy in the Earth’s outer core. A team of French researchers suggests that elastic deformation of our planet’s mantle due to tidal effects caused by the Moon — overlooked until now — transfers energy to the Earth’s outer core, keeping the geodynamo active.
Mars hasn’t always looked like it does today. Some 3 to 3.5 billion years ago, the planet underwent a huge tilt of 20 to 25 degrees. The gigantic Tharsis volcanic dome, which started to form over 3.7 billion years ago, grew so massive that it caused Mars’ crust and mantle to swivel around, shifting the Tharsis dome to the planet’s equator.
Twenty years after they were first discovered, ‘hot Jupiters’ — gas giant planets that orbit very close to their star — are still enigmatic objects. Using the Canada-France-Hawaii Telescope, an international team of astrophysicists has shown that such bodies may only take several million years to migrate close to their newly formed star.