高能粒子撞击地球

高能粒子撞击地球

ByNASA中文

2023年12月5日 Energetic Particle Strikes the Earth Illustration Credit: Osaka Metropolitan U./L-INSIGHT, Kyoto U./Ryuunosuke Takeshige Explanation: It was one of the most energetic particles ever known to strike the Earth — but where did it come from? Dubbed Amaterasu after the Shinto sun goddess, this particle, as do all cosmic rays that strike the Earth’s atmosphere, caused an air shower of electrons, protons, and other elementary particles to spray down onto the Earth below. In the featured illustration, a cosmic ray air shower is pictured striking the Telescope Array in Utah, USA, which recorded the Amaterasu event in 2021 May. Cosmic ray air showers are common enough that you likely have been in a particle spray yourself, although you likely wouldn’t have noticed. The origin of…

没PS过的仙女星系

没PS过的仙女星系

ByNASA中文

2019 October 14 Andromeda before Photoshop Image Credit: Kees Scherer Explanation: What does the Andromeda galaxy really look like? The featured image shows how our Milky Way Galaxy’s closest major galactic neighbor really appears in a long exposure through Earth’s busy skies and with a digital camera that introduces normal imperfections. The picture is a stack of 223 images, each a 300 second exposure, taken from a garden observatory in Portugal over the past year. Obvious image deficiencies include bright parallel airplane trails, long and continuous satellite trails, short cosmic ray streaks, and bad pixels. These imperfections were actually not removed with Photoshop specifically, but rather greatly reduced with a series of computer software packages that included Astro Pixel Processor, DeepSkyStacker, and PixInsight. All of…