  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.
