Category Astronomy/Space

Google Earth, Cornell University, Planetary Space Institute Thermal image showing ice-rich lobes (outlined by yellow line), which we interpret to be the remnants of tsunami waves that transitioned into slurry ice-rich flows as they propagated under extremely cold climatic conditions. Upslope direction of flow indicated by white arrow. The lobe is about 250 km in length, or the distance between Baltimore and New York City. Credit: Image courtesy of Cornell University; This view was produced using Google Earth

The geologic shape of what were once shorelines through Mars’ northern plains convinces scientists that 2 large meteorites – hitting the planet millions of years apart – triggered a pair of mega-tsunamis...

During periods when geomagnetic storms affect Earth, new low-energy protons (with energy of tens of thousands of electronvolts, or keV; shown here in magenta) enter the near-Earth region, enhancing the preexisting ring current (orange). Credit: Johns Hopkins APL

New findings based on a year’s worth of observations from NASA’s Van Allen Probes have revealed that the ring current – an electrical current carried by energetic ions that encircles our planet – behaves in a much different way than previously understood. The ring current has long been thought to wax and wane over time, but the new observations show that this is true of only some of the particles, while other particles are present consistently.

Using data gathered by the Radiation Belt Storm Probes Ion Composition Experiment, or RB...

Illustration of the dust ring surrounding HD 181327. Credit: Amanda Smith, University of Cambridge

Astronomers have found evidence of ice and comets orbiting a nearby sun-like star, which could give a glimpse into how our own solar system developed. Using Atacama Large Millimeter Array (ALMA), the researchers, led by the University of Cambridge, detected very low levels of CO around the star, in amounts that are consistent with the comets in our own solar system. The results are a first step in establishing the properties of comet clouds around sun-like stars just after the time of their birth.

Comets are essentially ‘dirty snowballs’ of ice and rock, sometimes with a tail of dust and evaporating ice trailing behind them, and are formed early in the development of stellar systems...

White dwarf (right) stripping mass from the brown dwarf. Credit: Rene Breton, University of Manchester.

Astronomers have detected a sub-stellar object that used to be a star, after being consumed by its white dwarf companion. An international team of astronomers made the discovery by observing a very faint binary system, J1433 730 light-years away. The system consists of a low-mass object – 60X the mass of Jupiter – in an extremely tight 78-min orbit around a white dwarf (the remnant of a star like our Sun).

Due to their close proximity, the white dwarf strips mass from its low-mass companion. This process has removed about 90% of the mass of the companion, turning it from a star into a brown dwarf...