Input of natural extraterrestrial material into our atmosphere


Daniel Kastinen Johan Kero

Meteors!

Perseid Meteor Shower 2023 ( youtube @MagicCarpetMedia )

Meteors!

    This presentation

  • Cover the basics of natural input & meteors
    (broad, interdisciplinary, ...)
  • If I didn't cover your question: ask us later!

Perseid Meteor Shower 2023 ( youtube @MagicCarpetMedia )

Meteors!

Where do meteoroids come from?

Rosetta OSIRIS - 67P/Churyumov-Gerasimenko

  • Comet sublimation
  • Asteroid collision
  • Catastrophic disruption
  • Dynamical perturbation
  • Impact ejecta
  • Interstellar?
  • ...

Meteoroid streams and meteor showers

Credit: www.meteorshowers.org

Meteors!

Where do meteoroids come from?

Meteors!

Where do meteoroids come from?

    Observed cometary sporadics:

  • (Jacchia et al. 1967):
    99% photographic
  • (Starczewski & Jopek 2004):
    22% radio, 52% photographic, 47% video
  • (Jopek & Williams 2013):
    67% all
  • No dynamics, instrumental bias, ...

Meteors!

Where do meteoroids come from?

    Observed streams:

  • (Ye 2018) IAU established showers
    ~87% cometary
  • History of "asteroids" -> comet activity

Meteors!

Where do meteoroids come from?

    Observed Streams vs Sporadic:

  • (Ceplecha et al. 1998)
    < 25% visual streams
  • (Brown et al. 2007)
    < 10% radar streams
  • (Jenniskens et al. 2015)
    26% optical streams
  • Sporadic dominates

The making of a meteor

The making of a meteor

Dyrud et al. 2008

John Plane, 2012

The measurement of a meteor

Meteors and space objects

    Mass influx estimates:

  • (Drolshagen et al. 2007)
    $30 - 180 t d^{-1}$
    Best guess: $32 - 54 t d^{-1}$
  • (Carrillo-Sánchez et al. 2020)
    $28 \pm 16 t d^{-1}$

Background credits: NASA/Reid Wiseman

John's legendary table

John Plane, "Cosmic dust in the earth's atmosphere", 2012

Background credits: NASA/Reid Wiseman

Radar meteor head echoes

Shigaraki Middle and Upper Atmosphere (MU) radar, Japan

Radar & optical meteor distributions

MU radar in Japan

Kastinen & Kero 2022

EMCCD optical system in Ontario, Canada

Mills et al. 2021

Meteoroids/asteroids that survive atmospheric entry?

Video: Chelyabinsk superbolide - Dash-cam footage February 15th 2013

Meteorites

UK Polar Meteorite Exploration and Research, Image by K Joy

Meteorites

UK Polar Meteorite Exploration and Research, Image by K Joy

  • Many types:
    stony, stony-iron, and iron meteorites
    Chondrites, achondrites, pallasites, mesosiderite, ...
  • (Schulz & Glassmeier 2021)
    Meteorites + in-situ collected dust + ...
    $\approx$ metal (31%), metalloid (13%), nonmetallic (47%), other (8%)
  • Tricky: meteorite bias, discovery bias, influx origin, ...

Synergies

  • Same instrumentation for re-entry and meteors
  • In principle same governing dynamics and ablation physics
    but different population characteristics
  • Different composition & origin (sometimes known!)

Future work

  • Fitting ablation to data is currently underdetermined
  • More meteorites with known orbits
  • Reconcile and improve total mass input estimates
  • -> Imrpove observations!
  • Improve meteoroid source models
  • ...

Video: AMS226 @ IRF roof - DK

Thank you for listening!

Video: AMS226 @ IRF roof - DK

Meteor cameras

Estimating mass

$$ \frac{1}{2}\pi R^2 \rho_a v^3 \Lambda = 4 \pi R^2 \sigma \epsilon ( T_s^4 - T_a^4) + \frac{4}{3}\pi R^3 \rho_m C \frac{dT_m}{dt} + L \frac{dm}{dt} \\ \frac{dv}{dt} = -\frac{\Gamma \rho_a \pi R^2 v^2}{m} $$
  • Atmosphere: density ${\color{8888FF}\rho_a}$, temperature ${\color{8888FF}T_a}$
  • Meteoroid state: velocity ${\color{green}v}$, surface and mean temperature ${\color{green}T_s, T_m}$
  • Meteoroid properties: radius ${\color{red}R}$, density ${\color{red}\rho_m}$, specific heat ${\color{red}C}$, head of vaporization ${\color{red}L}$, emissivity ${\color{red}\epsilon}$, drag parameter ${\color{red}\Gamma}$, mass ${\color{red}m}$

Single body, homogenous, spherical, ...