In the Aug. 19 SN: Bulletins from the tick wars, roots of Rwandan genocide, spin-resistant spiders, making mums blue, tardigrade saga continues, HIV antibodies from cows, Maxwell’s demon aces memory test and more.
SIGNS OF LINES The sun’s magnetic field is connected to one in the corona, which is much weaker and therefore harder to observe. Together, they form a twisted mess, illustrated here as white lines (based partly on a model) over a 2016 image of the sun from NASA’s Solar Dynamics Observatory.
NASA/SDO/AIA/LMSAL
CHARGED UP Auroras are triggered in Earth’s atmosphere by the solar wind, a constant stream of charged particles wafting away from the sun. This photo of an aurora was taken from the International Space Station on June 26.
NASA
Each day until August 21, astronomy writer Lisa Grossman will explore the top questions scientists will tackle during the 2017 total solar eclipse.
Rick Fienberg/TravelQuest International/Wilderness Travel (CC BY-NC-ND 4.0)
CRUNCH THE NUMBERS Scientists estimate that the Milky Way contains 100 million black holes.
AvigatorPhotographer/iStockphoto
