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, ...)
  • Some clear synergies from existing meteor research field
  • If I didn't cover your question: ask us later!

Perseid Meteor Shower 2023 ( youtube @MagicCarpetMedia )

Meteors!

Meteors!

Dyrud et al. 2008

John Plane, 2012

Meteors!

Where do meteoroids come from?

Rosetta OSIRIS - 67P/Churyumov-Gerasimenko

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

Meteors!

Where do meteoroids come from?

Credit: www.meteorshowers.org

Meteors!

Where do meteoroids come from?

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

Atmospheric mass influx

Natural input

  • (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

Atmospheric mass influx

Anthropogenic input

  • See next talk by Leonard!

Background credits: NASA/Reid Wiseman

Meteors and space objects

A variety of observations methods

Meteors and space objects

Adjacent and slightly overlapping populations

    Meteoroids

  • ~10 - 72 km / s
  • $10^{-9}$ - $10^{2}$ g
  • Silicates and organics to iron
  • Deep trajectories
  • Majority of influx
  • Steady-ish population

    Artificial space objects

  • ~8 km / s
  • $10^{-1}$ - $10^{6}$ g
  • Batteries to alloys
  • Shallow trajectories
  • Still small influx
  • Massive changes ongoing

The measurement of a meteor

The measurement of a resident space object

The measurement of a re-entry

Meteors and space objects

There is a of synergy between the two topics

    Questions is:

  • What do we need to measure?
  • What new models do we need to develop?
  • How can we adapt current methods and technology?

    • And today's first presentation addressed exactly that!

So here are some examples of observational synergy

Meteors and space objects

For example: meteor trail radars and re-entries

SIMONe observations of dusty plasma after a Falcon-9 re-entry

Figure credits: Juha Vierinen
Instrument credit: Institute of Atmospheric Physics, Jorge Chau

Figure credits: Juha Vierinen
Instrument credit: Institute of Atmospheric Physics, Jorge Chau

Meteors and space objects

For example: allsky meteor cameras and re-entries

Meteor cameras covers much of Earth's surface

Falcon-9 re-entry observed by many meteor cameras

Credit: André Knöfel, AllSky7 network

Falcon-9 re-entry observed by many meteor cameras

Image credit: Felix Bettonvil, Leiden University, Location: Dwingeloo, Netherlands

Meteors and space objects

For example: High-power Large-aperture radars

Credit: EISCAT

  • The EISCAT radars
  • Contributed to meteor research for decades
  • But also one of the data sources for calibrating the ESA space debris environment model

Meteors and space objects

For example: High-power Large-aperture radars

(Kastinen et al. Acta Astronautica, 2023)

Meteors and space objects

For example: High-power Large-aperture radars

What about re-entries?

Still unclear what we can detect...
The big ones: yes when they occur within field of view
small ones: ?

Some needed work

  • Better fitting of ablation models to data
  • Figure out radar detectability of re-entires
  • Start utilizing all available instrumentation
  • Define the critical questions and how to address them observationally
  • And more of course! ...

Thank you for listening!

Video: AMS226 @ IRF roof - DK