2 research outputs found
Location, orbit and energy of a meteoroid impacting the moon during the Lunar Eclipse of January 21, 2019
During lunar eclipse of January 21, 2019 a meteoroid impacted the Moon
producing a visible light flash. The impact was witnessed by casual observers
offering an opportunity to study the phenomenon from multiple geographical
locations. We use images and videos collected by observers in 7 countries to
estimate the location, impact parameters (speed and incoming direction) and
energy of the meteoroid. Using parallax, we achieve determining the impact
location at lat. , lon. and
geocentric distance as 356553 km. After devising and applying a photo-metric
procedure for measuring flash standard magnitudes in multiple RGB images having
different exposure times, we found that the flash, had an average G-magnitude
. We use gravitational ray tracing (GRT) to
estimate the orbital properties and likely radiant of the impactor. We find
that the meteoroid impacted the moon with a speed of km/s (70%
C.L.) and at a shallow angle, degrees. Assuming a normal error
for our estimated flash brightness, educated priors for the luminous efficiency
and object density, and using the GRT-computed probability distributions of
impact speed and incoming directions, we calculate posterior probability
distributions for the kinetic energy (median = 0.8 kton), body
mass ( = 27 kg) and diameter ( = 29 cm), and crater
size ( = 9 m). If our assumptions are correct, the crater left by
the impact could be detectable by prospecting lunar probes. These results arose
from a timely collaboration between professional and amateur astronomers which
highlight the potential importance of citizen science in astronomy.Comment: 19 pages, 11 figures, 4 tables. Data and scripts available in
https://github.com/seap-udea/MoonFlashes. Accepted for publication in MNRA