Free Republic

The Universe is a large place, and there are a lot of large things in it. Not just galaxies, but groupings of galaxies, and the cosmic web that connects them all together. Scientists have just discovered what appears to be one of these groupings, and it could have serious implications for our understanding of the evolution of the Universe. It's an almost-symmetrical arc of galaxies at a distance of 9.2 billion light-years away, and, at 3.3 billion light-years across, it's one of the biggest structures ever identified. Astronomers are calling it the Giant Arc, and, if confirmed, it joins a...

Artist’s impression of cosmic filaments: huge bridges of galaxies and dark matter connect clusters of galaxies to each other. Galaxies are funneled on corkscrew like orbits towards and into large clusters that sit at their ends. Their light appears blue-shifted when they move towards us, and red-shifted when they move away. Credit: AIP/ A. Khalatyan/ J. Fohlmeister ==================================================================================== By mapping the motion of galaxies in huge filaments that connect the cosmic web, astronomers at the Leibniz Institute for Astrophysics Potsdam (AIP), in collaboration with scientists in China and Estonia, have found that these long tendrils of galaxies spin on the...

Explanation: What's creating these long glowing streaks in the sky? No one is sure. Known as Strong Thermal Emission Velocity Enhancements (STEVEs), these luminous light-purple sky ribbons may resemble regular auroras, but recent research reveals significant differences. A STEVE's great length and unusual colors, when measured precisely, indicate that it may be related to a subauroral ion drift (SAID), a supersonic river of hot atmospheric ions thought previously to be invisible. Some STEVEs are now also thought to be accompanied by green picket fence structures, a series of sky slats that can appear outside of the main auroral oval that...