Introduction
Japanese astronomer Daichi Fujii, curator of the Hiratsuka City Museum, recently captured two meteors colliding with the moon on October 30 and November 1. These events, which produced brief yet brilliant flashes of light, were observed from Earth and highlight the ongoing activity of meteoroids impacting the lunar surface, particularly in conjunction with the upcoming Southern and Northern Taurid meteor showers.
Details of the Observations
The first meteor impact was recorded on October 30 at 8:30 p.m. Japan Standard Time (6:30 a.m. EST or 1130 GMT). Fujii noted that this flash occurred east of the Gassendi Crater, with the meteoroid likely being part of the Taurid meteor stream. The object struck the moon at a remarkable speed of 27 kilometers per second (approximately 60,000 miles per hour) and at an angle of 35 degrees, resulting in the creation of a crater about 10 feet (3 meters) wide. The flash lasted only 0.1 seconds, and Fujii indicated that the brightness may have exceeded the recorded data due to pixel saturation.
The second impact took place on November 1 at 8:49 p.m. Japan Standard Time (6:49 a.m. EST or 1149 GMT), appearing west of Oceanus Procellarum, one of the largest maria on the moon. While it remains uncertain whether the second impact was also from the Taurid meteor shower, the timing suggests a correlation with the period of increased meteor activity associated with this celestial event.
Fujii's Ongoing Research
Daichi Fujii has been systematically observing lunar impact flashes since 2011 and has intensified his efforts since 2020. Using a 20-centimeter telescope, he typically identifies about one impact flash every several dozen hours of observation. However, due to the moon's thin crescent phase and its low position in the sky, which often coincides with cloud cover, he manages to detect only a few dozen flashes each year. To date, he has documented a total of 60 such flashes.
Impact Dynamics on the Moon
Unlike Earth, which benefits from a thick atmosphere that disintegrates most meteors before they reach the ground, the moon has an almost nonexistent atmosphere. This absence allows meteoroids to strike the lunar surface at speeds ranging from 45,000 to 160,000 miles per hour (20 to 72 kilometers per second). Such impacts can create craters that are tens of feet wide, even from relatively small meteoroids weighing only a few pounds. For instance, a meteoroid weighing approximately 11 pounds (5 kilograms) can produce a crater over 30 feet (9 meters) wide and eject significant amounts of lunar material, as noted by NASA.
Conclusion
The recent observations by Daichi Fujii not only underscore the dynamic nature of the moon's surface but also reflect the broader context of ongoing meteor activity associated with the Taurid meteor showers. As astronomers continue to monitor these impacts, they contribute valuable data to our understanding of the interactions between celestial bodies and the potential implications for planetary science. Fujii's work exemplifies the importance of amateur astronomers in advancing our knowledge of space phenomena, highlighting the unique characteristics of lunar impacts compared to those on Earth.