Aurora Aurora An aurora (plural: auroras or aurorae), sometimes referred to as polar lights, northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in the Earth's sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic). Auroras are produced when the magnetosphere is sufficiently disturbed by the solar wind that the trajectories of charged particles in both solar wind and magnetospheric plasma, mainly in the form of electrons and protons, precipitate them into the upper atmosphere (thermosphere/exosphere) due to Earth's magnetic field, where their energy is lost. The resulting ionization and excitation of atmospheric
Dimetrodon borealis the sabre-armed jaws completed the sanguinary work of destruction." American paleontologist E. C. Case reclassified "Bathygnathus" as a pelycosaur (a type of "mammal-like reptile") in 1905, noting its similarities with the genus "Dimetrodon", a sail-backed synapsid that was discovered in Texas in the 1870s. In their 1940 overview of pelycosaurs, Alfred Romer and Llewellyn Ivor Price suggested that "Bathygnathus" might be synonymous with "Dimetrodon". Dimetrodon borealis Dimetrodon borealis, formerly known as "Bathygnathus borealis," is an extinct species of pelycosaur-grade synapsid that lived about 270 million years ago (Ma) in the Early Permian. A partial maxilla or upper jaw bone from