Equilibrium chemistry of the atmospheres of hot earth like exoplanets
This presentation is the property of its rightful owner.
Sponsored Links
1 / 13

Equilibrium Chemistry of the Atmospheres of Hot Earth-like Exoplanets PowerPoint PPT Presentation


  • 53 Views
  • Uploaded on
  • Presentation posted in: General

Equilibrium Chemistry of the Atmospheres of Hot Earth-like Exoplanets. Laura Schaefer Katharina Lodders Bruce Fegley, Jr. Introduction. Currently, there are several hundred known exoplanets 24 super-Earths ( M < 10 M Earth )

Download Presentation

Equilibrium Chemistry of the Atmospheres of Hot Earth-like Exoplanets

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Equilibrium chemistry of the atmospheres of hot earth like exoplanets

Equilibrium Chemistry of the Atmospheres of Hot Earth-like Exoplanets

Laura Schaefer

Katharina Lodders

Bruce Fegley, Jr


Introduction

Introduction

  • Currently, there are several hundred known exoplanets

    • 24 super-Earths (M < 10MEarth)

    • Number of known exoplanets should go up considerably in February (Kepler releases data).

  • The Kepler and CoRot missions are dedicated space telescopes that are looking for transiting exoplanets

  • Some of the discovered exoplanets, such as CoRot-7b, are very hot

  • Here we report results for an Earth-like planet hot enough to vaporize its crust

  • Our results will be useful for spectroscopic studies of the atmospheres of hot super-Earths


Methods

Methods

  • Chemical equilibrium calculations with a Gibbs energy minimization code

    • bulk system has abundances of the terrestrial continental crust

    • 1200 gases, 400 solid compounds included

  • T= 500 – 4000 K

  • P = 10-6 – 10+2.5 bars

    • Results here are for 100 bars unless otherwise stated


Major gas chemistry

Major Gas Chemistry

Lithophiles

Na, K, Fe, Mg,

Si, Ti, Ca, Al

Volatiles

H, C, N, O, S


Major gas chemistry1

Major Gas Chemistry

  • Molecular N2 is the major gas below ~500 K

  • From 500 – 3400 K, the major gas is H2O

    • CO2 is second most abundant gas

  • Molecular O2 is major gas from 3400 – 3900 K

  • At higher temperatures, SiO gas is the most abundant gas


Major gas chemistry2

Major Gas Chemistry


Major gas chemistry3

Major Gas Chemistry

Lithophiles

Na, K, Fe, Mg,

Si, Ti, Ca, Al

  • Lithophile gases are dominated by Na and K below ~3600 K

    • Halides (F,Cl) + Hydroxides

  • Above ~3600 K, SiO and SiO2 are the most abundant lithophile gases


Major gas chemistry4

Major Gas Chemistry


Major gas chemistry5

Major Gas Chemistry


Condensates

Condensates

  • Graph shows the gas/condensed phase mole ratio for different total pressures

    • Higher ratio = more gas present

  • At high pressure, condensed phases persist to very high temperature


Condensates1

Condensates

  • Graph shows the gas/condensed phase mole ratio for different total pressures

    • Higher ratio = more gas present

  • At high pressure, condensed phases persist to very high temperature

  • At low pressure, complete evaporation occurs at lower temperatures


Summary

Summary

  • Continental crust produces an H2O + CO2 atmosphere over a broad temperature range at 100 bars

  • At very high temperatures O2 and SiO gas dominate

    • Alkali gases (e.g., KOH, KCl, NaOH, NaCl) are very abundant

  • In future work, we will explore differences in gas chemistry for a variety of interesting compositions

    • Oceanic crust, Bulk Silicate Earth, Moon, meteoritic compositions, etc.

    • Any requests?


Major gas summary

Major Gas Summary

H2O

OH

CO2

CO

N2

NO

Volatiles

H2O

O2

SiO

SO2

SiO2

SiO

FAl(OH)2

Al(OH)3

FAlO

AlO

FeCl2

Fe(OH)2

FeO

CaF2

CaFOH

Ca(OH)2

Lithophiles

NaCl

NaOH

Na

Mg(OH)2

MgO

KCl

KOH

K

TiO2


  • Login