Meteor Fireballs in Light and Sound
Image Credit & Copyright: Thomas Ashcraft (Radio Fireball Observatory)
Explanation: Yes, but have you ever heard a meteor? Usually, meteors are too far away to make any audible sound. However, a meteor will briefly create an ionization trail that can reflect a distant radio signal. If the geometry is right, you may momentarily hear — through your radio — a distant radio station even over static. In the featured video, the sounds of distant radio transmitters were caught reflecting from large meteor trails by a sensitive radio receiver — at the same time the bright streaks were captured by an all-sky video camera. In the video, the bright paths taken by four fireballs across the sky near Lamy, New Mexico, USA, are shown first. Next, after each static frame, a real-time video captures each meteor streaking across the sky, now paired with the sound recorded from its radio reflection. Projecting a meteor trail down to the Earth may lead to finding its impact site (if any), while projecting its trail back into the sky may lead to identifying its parent comet or asteroid.
Almost Hyperspace: Random APOD Generator
Tomorrow’s picture: astro dust
火流星的光与声
影像提供与版权: Thomas Ashcraft (Radio Fireball Observatory)
说明: 你听过流星发出的声音吗？流星通常太遥远，只见其影而不闻其声。然而流星会产生短暂的电离痕，可反射远方的无线电讯号。如果相对的几何位置搭配得宜，纵然有静电干扰声，还是可透过收音机，短暂听到远方广播电台的广播，就如这部主题影片所示。影片中，从火流星迹反射的远方无线电发射器之声波，是由灵敏的无线电接收器所收录，而同步呈现的明亮光痕，则是来自全天照相机。这部摄于美国新墨西哥州拉米地区的影片，首先呈现4颗火流星的明亮光痕。接着在每幅静态影像之后，呈现那颗流星掠过长空的实况，同时搭配上所反射的无线电讯号。流星痕在地球的投影，可让我们找到它的撞击点（如果未完全燃尽）。而回溯流星在天空的流星痕，可找到作为它母源的彗星或小行星。
几乎超空间：随机APOD生成器
明日的图片: astro dust
