Multiwavelength observations of a bright impact flash during the January 2019 total lunar eclipse

TL;DR

This paper reports the first unambiguous observation of a lunar impact flash during a total lunar eclipse, using multiwavelength data to analyze its properties, origin, and the resulting crater, providing new insights into lunar impact phenomena.

Contribution

It presents the first multiwavelength observations of a lunar impact flash during an eclipse and analyzes its temperature, origin, and crater size, advancing lunar impact research.

Findings

Impact flash lasted 0.28 seconds with brightness of mag. 4.2.

Blackbody temperature of the flash was about 5700 K.

Estimated crater diameter and projectile source were determined.

Abstract

We discuss here a lunar impact flash recorded during the total lunar eclipse that occurred on 2019 January 21, at 4h 41m 38.09 +- 0.01 s UT. This is the first time ever that an impact flash is unambiguously recorded during a lunar eclipse and discussed in the scientific literature, and the first time that lunar impact flash observations in more than two wavelengths are reported. The impact event was observed by different instruments in the framework of the MIDAS survey. It was also spotted by casual observers that were taking images of the eclipse. The flash lasted 0.28 seconds and its peak luminosity in visible band was equivalent to the brightness of a mag. 4.2 star. The projectile hit the Moon at the coordinates 29.2 +- 0.3 $^{\circ}$S, 67.5 +- 0.4 $^{\circ}$W. In this work we have investigated the most likely source of the projectile, and the diameter of the new crater generated by the collision has been calculated. In addition, the temperature of the lunar impact flash is derived from the multiwavelength observations. These indicate that the blackbody temperature of this flash was of about 5700 K.