2025年8月12日

Perseids from Perseus

Image Credit & Copyright: Marcin Rosadziński

Explanation: Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Perseus. That is why the meteor shower that peaks tonight is known as the Perseids — the meteors all appear to come from a radiant toward Perseus. In terms of parent body, though, the sand-sized debris that makes up the Perseids meteors come from Comet Swift-Tuttle. The comet follows a well-defined orbit around our Sun, and the part of the orbit that approaches Earth is superposed in front of Perseus. Therefore, when Earth crosses this orbit, the radiant point of falling debris appears in Perseus. Featured here, a composite image taken over six nights and containing over 100 meteors from 2024 August Perseids meteor shower shows many bright meteors that streaked over the Bieszczady Mountains in Poland. This year’s Perseids, usually one of the best meteor showers of the year, will compete with a bright moon that will rise, for many locations, soon after sunset.

Tomorrow’s picture: orion’s stellar heart

英仙座的英仙流星雨

影像提供与版权: Marcin Rosadziński

说明: 这些流星究竟来自何方？就天空的位置来说，答案是英仙座。这些流星看起来全都来自英仙座方向的辐射点，而这也是为何极大期在今晚的这群流星，名为英仙流星雨的原因。然而，从其源头来说，产生英仙流星雨的沙粒大小碎片，源自史威福-塔托彗星。这颗彗星沿着明确的轨道绕行太阳，而这个轨道最接近地球的区域，正好在英仙座的前方。因此，当地球穿过这个轨道区时，碎片洒落的辐射点就位于英仙座内。上面这幅组合了6个夜晚数据的主题影像，记录了2018年英仙座流星雨期间的100多颗流星，包括许多掠过 波兰贝什恰迪山脉（Bieszczady Mountains）上空的明亮流星。英仙座流星雨通常是每年最活跃的流星雨群之一，而今年观赏英仙流星雨的最佳时间，是在明月西落后的清晨。

明日的图片: orion’s stellar heart