H mag of 11? Wowza! I hope we get some albedo measurements.

Another handheld video from closer by!

for the first time, we were able to compare telescopic observations of an asteroid to later fireball camera observations of it as it burned up -- both techniques agree really well: *2022 WJ1 was the smallest asteroid ever characterized in space*. [woo-hoo!]

We plan to apply this approach to many more meteors from more showers, enabling us to remotely probe the composition of comets. We also plan to create a catalogue of models for each shower including full fragmentation, enabling the use of these advanced models in the community.

These findings are different from what Kikwaya et al. (2011) found (figure below), especially for objects on Jupiter-family orbits. They found very high densities of ~3500 kg/m3, which would make them solid silicates with no porosity, which does not match in situ ROSETTA findings

We find that meteoroids from Halley-type comets have bulk densities 200 - 500 kg/m3 (~90% porosity), and shower meteoroids from Jupiter-family comets are only slightly denser at 500-1000 kg/m3. The #Geminids are much denser, ~1400 kg/m3, pointing to carbonaceous composition.

The model assumes that cometary meteoroids are composed of small silicate grains and are fluffy, just like dust observed by
@ESA_Rosetta
and collected in the stratosphere with repurposed U2 spy planes.

We have carefully fit a meteor fragmentation model to 41 meteors from meteor showers with known parent bodies to learn about the composition of specific comets. The model accurately reproduces the wake, directly informing the structure of the meteoroid.

We use the Canadian Automated Meteor Observatory's mirror-tracking system to observe meteors in unprecedented detail, seeing details of fragmentation and wake for each meteor

Here is a good first-person account by Ruth: www.theguardian.com/lifeandstyle...

"... she heard a large bang and then looked up to find a hole in her ceiling and a fist-sized rock on her bed. Hamilton advised the rock gave off a burnt metallic smell and appears it was the rock that created the hole down through her ceiling." 2021-10-03 at 23:50 MST

a = 2.512 AU
e = 0.6295
i = 11.911 deg
peri = 215.044 deg
node = 189.219 deg