Astro Blog

By Phie Jacobs , Science.  Excerpt: Researchers...aren’t quite sure why...the corona, is so much hotter than the Sun’s surface—or why it can violently eject huge volumes of plasma that can mess with Earth’s magnetic field and scramble power grids. ...air turbulence in Earth’s atmosphere blurs our view of it, making it hard to discern fine details. Now, using an adaptive optics system installed at Big Bear Solar Observatory (BBSO), the authors of a new  Nature Astronomy  study have removed this blur—producing  the clearest images and videos to date of the Sun’s atmosphere . In  a statement , BBSO optical engineer and study co-author Nicolas Gorceix likened the new technology to “a pumped-up autofocus and optical image stabilization in your smartphone camera, but correcting for the errors in the atmosphere rather than the user’s shaky hands.” ...researchers also captured a phenomenon known as coronal rain, where city-size droplets of hot plasma in the Sun’s corona...

By  Jamie M. Jasinsk  et al, Nature Astronomy. Summary: A human spacecraft has only gotten close to Uranus once—in 1986, when Voyager 2 drifted past the distant planet. That flyby indicated that   Uranus was weird in several ways , which astronomers have spent decades trying to explain. Now, a new analysis in   Nature Astronomy   suggests the probe   just happened to arrive there on an off day . Voyager 2’s data indicated that Uranus had an “unusually oblique and off-centered magnetic field” with inexplicably intense electron radiation belts and a severely plasma-depleted magnetosphere,” the team behind the new work writes. But by mining old data from the mission, the scientists found evidence for a super strong solar wind that likely squished the magnetosphere just prior to the probe’s readings. This would have pushed any plasma too close to the planet to detect, and filled the radiation belts with high-energy particles. https://www.nature.com/articles/s41...

https://eos.org/articles/magnetic-tangles-drive-solar-wind By  atthew R. Francis , Eos/AGU.  Excerpt: Though the  effects  of solar wind are well documented, what  causes  it has been a mystery for more than 50 years. Now, thanks to a solar close-up, some researchers think the energy behind the flow of particles comes from the Sun’s own magnetic fields snapping together. The process, known as reconnection, may illuminate not only solar wind but winds from other stars as well as the behavior of comets and planetary atmospheres. In part to solve the solar wind mystery—and perhaps learn ways to spot solar storms before they form—researchers developed NASA’s  Parker Solar Probe , which launched in 2018 and has been flying in ever-closer orbits to the Sun. ...Reconnection occurs in plasmas when magnetic fields pointing in opposite directions cancel out, rapidly dumping their energy into the surrounding electrons and ions. A simplified picture would be takin...

https://www.science.org/content/article/mars-had-long-lived-magnetic-field-extending-chances-life By Zack Savitsky, Science.  Excerpt: Once upon a time, scientists believe, Mars was far from today’s cold, inhospitable desert. Rivers carved canyons, lakes filled craters, and a magnetic field may have fended off space radiation, keeping it from eating away the atmospheric moisture. As the martian interior cooled, leading theories hold, its magnetic field died out, leaving the atmosphere undefended and ending this warm and wet period, when the planet might have hosted life. But researchers can’t agree on when that happened. Now, fragments from a famous martian meteorite, studied with a new kind of quantum microscope, have yielded evidence that the planet’s field persisted until 3.9 billion years ago, hundreds of millions of years longer than many had thought. The clues in the meteorite, a Mars rock that ended up on Earth after an impact blasted it from its home planet, could extend Ma...