火箭凌越波纹月

2024年1月2日

Rocket Transits Rippling Moon
Image Credit & Copyright: Steven Madow

Explanation: Can a rocket make the Moon ripple? No, but it can make a background moon appear wavy. The rocket, in this case, was a SpaceX Falcon Heavy that blasted off from NASA‘s Kennedy Space Center last week. In the featured launch picture, the rocket’s exhaust plume glows beyond its projection onto the distant, rising, and nearly full moon. Oddly, the Moon’s lower edge shows unusual drip-like ripples. The Moon itself, far in the distance, was really unchanged. The physical cause of these apparent ripples was pockets of relatively hot or rarefied air deflecting moonlight less strongly than pockets of relatively cool or compressed air: refraction. Although the shot was planned, the timing of the launch had to be just right for the rocket to be transiting the Moon during this single exposure.

Tomorrow’s picture: red sky arc

火箭凌越波纹月
影像提供与版权: Steven Madow

说明: 火箭能让月球产生涟漪吗？不能，但它可以让背景的月亮看似带着波纹。在此例里，这枚于上星期从美国国家航空航天局肯尼迪航天中心发射升空的火箭，是太空探索技术公司的猎鹰重型运载火箭。在这幅记录其发射景观的主题影像里，火箭的明亮排气羽流之伸展范围，覆盖并超出远后方接近满相的东升明月。很奇特的是，月盘的下缘带着不寻常的滴水状波纹。其实，远方的月亮本身并没有任何改变。这些视觉上的波纹之物理成因，是相对较热（较稀薄）的空气胞，对月光的折射低于相对较冷（较致密）的空气胞所产生之蜃影。尽管此次拍照是计划好的，但火箭发射的时间点必须恰好，才能让它在拍照期间凌越月亮。

明日的图片: red sky arc