Category Astronomy/Space

Because they are so distant from the Earth, Centaurs appear as pinpricks of light in even the largest telescopes. Saturn’s 200-km moon Phoebe, depicted in this image, seems likely to be a Centaur that was captured by that planet’s gravity at some time in the past. Until spacecraft are sent to visit other Centaurs, our best idea of what they look like comes from images like this one, obtained by the Cassini space probe orbiting Saturn. NASA’s New Horizons spacecraft, having flown past Pluto six months ago, has been targeted to conduct an approach to a 45-km wide trans-Neptunian object at the end of 2018. Credit: NASA/JPL-Caltech/Space Science Institute

The discovery of hundreds of giant comets in the outer planetary system over the last 2 decades means that these objects pose a much great...

Magnetic field lines (purple) are twisted as they are dragged inward toward a swirling, dusty disk surrounding a young star in this artist’s conception. CREDIT: Bill Saxton, NRAO/AUI/NSF.

Using new images with unprecedented detail, scientists have found material rotating around a very young protostar probably has dragged in and twisted magnetic fields from the larger area surrounding the star. The discovery, made with the Very Large Array VLA) radio telescope, has important implications for how dusty disks – the raw material for planet formation – grow around young stars.

The scientists studied a young protostar 750 light-years from Earth in constellation Perseus...

Einstein’s Cross. Credit: Image courtesy of Asociación RUVID

The Spanish interuniversity group has obtained precise measurements for the innermost region of a disc of matter in orbital motion around a supermassive black hole tucked inside the quasar known as Einstein’s Cross (Q2237-0305). It constitutes the most precise set of measurements achieved to date for such a small and distant object, and was made possible thanks to years of monitoring as part of the OGLE and GLITP gravitational microlensing projects, which have had their lenses trained on this quasar for 12 and 9 years, respectively.

Typically, astronomers can only detect bright objects that emit a lot of light or large objects that block background light...

On the left is and aurora oval before the auroral breakup occurs On the right is a supercomputer simulation reveals how auroral breakups develop Hot charged particles, or plasmas, gather in near-Earth space – just above the upper atmosphere of the polar region – when magnetic field lines reconnect in space. This makes the plasma rotate, creating a sudden electrical current above the polar regions. Furthermore, an electric current overflows near the bright aurora in the upper atmosphere, making the plasma rotate and discharge the extra electricity. This gives rise to the ‘surge’, the very bright sparks of light that characterize substorms. Credit: Kyoto University

A supercomputer model revealed the rotation of plasma creates electrical currents in the near-Earth space, ultimately triggering...