Planetary Atmosphere With ALMA

Raphaël Moreno

Observatoire de Paris-Meudon

Planetary atmosphere science

• Composition : Vertical distribution of species

Search for new species• Thermal structure: P(T)• Dynamics : winds • 3D mapping and monitoring: seasonal variations

Constraints on the origin and evolution of planets and the formation of the solar system

Observations with ALMA

HIGHLY IMPROVED

•Spatial resolution : Mapping of species

•Sensitivity : Search for new species

•Bandwidth : Large tropospheric lines

•Spectral resolution : Narrow stratospheric lines

Line profile / Winds

Mapping Planets with ALMA

Apparent diameter:

Planets : 2-60 “

Satellites & Pluto : 0.1-1”

ALMA spatial resolution : 0.1-0.01 “

0.01 “ (3-300 km @ 0.4-40 AU)

biggest planets limited to low frequency

Planetary and satellites atmospheres (DRSP theme: 4.1 )

•Dynamic of Mars and Venus atmosphere

•3D water cycle of Mars

•Chemistry of the atmosphere of Mars and Venus

•Composition and dynamic of giant planet stratosphere

•Search for broad line in the troposphere of the giant planets

•Chemical-dynamical coupling in Titan’s atmosphere

•Volcanism in Io

•The atmosphere of Triton, Pluto and other TNO objects

Mars - WindCO Doppler lineshift (mm):

Strong retrograde wind

GCM: prograde winds

ALMA:

3D-maps of winds and P(T)

Constrains on the dynamic and thermal structure

IRAM PdB Moreno 1999

Mars – water cycle

OVRO HDO 226 GHz (Gurwell)

mm observations of HDO :

Probe H2O near the surface

ALMA:

3D- field of water

H2O gas/ice interaction at different seasons

Mars – Photochemistry

JCMT – Clancy etal 2004

H2O2 recently detected mm/IR

ALMA:

•3D-maps of H2O2

•Search for new species :

HO2, H2CO, NO

VENUS

Atm. : CO2,N2+ traces of H2O, S-bearing species

mm/submm: CO and isotopes,

winds, HDO

ALMA:

•Search for : HCL, H2S, SO2

•3D-maps of CO, HDO

Dynamics and thermal structure

H2O spatial distribution

Photochemistry

CO(2-1) Bulh etal 91

Giant planets – Troposphere

JCMT – Weisstein etal 96

Composition : H2, He, CH4, H2O, NH3(J,S), PH3(J,S)

mm/submm : PH3(J+S), CO(N)

ALMA:

•Search for new species :

PH3 (U,N), CO(U), isotopes

•3D-Maps PH3, CO, P(T)

Planets formation and evolution

Giant Planets - Stratosphere

Composition : H2, He, CH4, H2O

mm/submm: CO(J,N), HCN(J,N)

CS(J), H2O

ALMA:• 3D-maps of CO, HCN • Search for CO(U), HCN(U),

HDO, Isotopes

Origin of external water JCMT- Marten etal 04

Titan Dense and cold : N2/CH4

mm/submm : CO and HCN

isotopes, HC3N, CH3CN, winds

ALMA:

•Search for more complex species

•3D-Maps of nitriles

Dynamics/photochemistry coupling

Complement observations to CASSINI

IRAM-PdB Moreno 03

Io

IRAM-30m Lellouch 03

Tenuous SO2 atmosphere

mm/submm: SO, SO2 and NaCl

ALMA:

•Search for new species (OCS, S2O, KCL)

•3D-Maps detected species

Atmosphere origin : Volcanism/sublimation

Pluton-Triton

Pluton-Charon

HST- separation 0.9”

Tenuous N2 atmosphere

mm/submm: CO upper limits

ALMA:

Search for CO

Atmospheric Temperature