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Gravity data details Ceres wandering pole

Gravity data details Ceres wandering pole

Science
Oct. 8 (UPI) -- Ceres, the solar system's innermost dwarf planet, features a wandering pole, new research confirms. Using gravity data collected by NASA's Dawn mission, researchers at the Planetary Science Institute were able to map density variations in Ceres crust, revealing topographical anomalies best explained by a polar reorientation. "The topography shows the remnants of an equatorial ridge compatible with the position of the paleo-equator," researchers wrote in a paper published this week in the journal Nature Geoscience. The axis around which a planetary body spins affects the density of the body's outer layers, including the crust. When the axis shifts and poles reorient themselves, crustal or topographical anomalies can emerge. On Ceres, scientists found evidence of a former e...
Gravity signals rapidly show true size of giant quakes

Gravity signals rapidly show true size of giant quakes

Science
Researchers have developed a new approach to estimate the true size of very large earthquakes. At present, scientists use seismic waves from a rupture to work out the scale of the event.But a new analysis of the Tohoku earthquake in Japan in 2011 shows that changes in gravity can give more rapid information.This method could have accurately estimated that magnitude 9 tremor in minutes, not the hours actually taken.As Japan's largest recorded earthquake, the Tohoku event is probably best remembered for the huge tsunami it unleashed. As well as killing around 12,000 people it triggered the meltdown of three nuclear reactors at the Fukushima Daiichi power plant. Experts believe that the quake was caused by the rupture of a stretch of the subduction zone associated with the Japan Trench, which...
Europe selects grand gravity mission

Europe selects grand gravity mission

Science
It is set to be one of the major science projects of the 2030s. The European Space Agency has just given the green light to the LISA mission to detect gravitational waves. This will see lasers bounced between three identical satellites separated by 2.5 million km. By looking for tiny perturbations in these light beams, the trio hope to catch the warping of space-time that is generated by cataclysmic events such as the merger of gargantuan black holes. Ground-based laboratories in the US have recently begun detecting gravitational waves from coalescing objects that are 20-30 times the mass of our Sun. But by sending an observatory into space, scientists would expect to discover sources that are millions of times bigger still and to sense their activity all the way out to the edge of the ob...