Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.cosmos.ru/conf/2009elw/presentations/presentations_pdf/session7/gerasimov_ELW.pdf Дата изменения: Mon Mar 2 19:59:32 2009 Дата индексирования: Mon Apr 6 23:54:12 2009 Кодировка: Поисковые слова: neutron

SCIENTIFIC TASKS OF THE GAS ANALYTIC PACKAGE FOR THE EUROPA LANDER.

, Space Research Institute, Russian Academy of Sciences, Moscow

M. V. Gerasimov

International Workshop "EUROPA LANDER: Science Goals and Experiments", February 9-13 2009, IKI, Moscow


The main scientific question: IS EUROPA HABITABLE?
Liquid water

Nutrients, chemicals and appropriate environment for complex organics

?

Energy sources (radiation, sunlight, redox couples)

Other questions: Origin of the Jupiter satellites? Evolution of an icy planetary body in space and under huge radiation? Other


Three main goals of the Lander: 1) Characterization of physical and chemical conditions at surface of Europa; 2) Search for biological activity; 3) Internal structure (thickness of ice, depth of the ocean, silicate core).


Characterization of physical and chemical conditions at surface of Europa

· Chemical composition of ices: Concentration of main and trace components. · Concentration and composition of organic components. · Key isotopic ratios: 13/12, D/, 17/16, 18/16. · Measure key habitability parameters: T, pH, Eh, electrical conductivity, radiation conditions, redox couples


Tasks for search of biological activity
· · · · · Characterize potential habitability of Europa Search for characteristic organic molecules as indication of extinct/extant life Search for environmental modifications induced by metabolic products: homochirality, specific isotopic fractionation Search for inorganic signs of life (biogenic gases (4, 2S, etc.)) Search for cells and/or cells remnants


Scientific tasks for the Gas Analytic Package:
· Measurement of chemical composition of volatile components of ices: Concentration of main and trace components. · Measurement of concentration and composition of organic components. · Search for biogenic gases (4, 2S, etc.) · Measurement of isotopic ratios 13/12, D/, 17/16, 18/16 in and . 2 2


Oxygen isotopes in the Solar System
8 Primitive water Ordinary chondrites Earth SNC meteorites (Mars) Moon

CI

6 4

17O,

2

CH CR

CM

0 -2

Carbonaceous chondrites

-4 -6

CV CO
0 5 10 15

18O,


Hydrogen isotopes in the Solar System


Gas analytic package for Europa Lander
Ice Melting O2 supply for combustion of organics Adsorption trap 1 Pyrolysis (DSC) of refractory residua (heavy organics, ...) pH Heater for vaporization of main ice components (2, 2, ...)

Adsorption trap 2 for gases which are released during melting (NH3, N2, CO, CH4, NG, light organics, ...)

Gas chromatograph

Massspectrometer

Tunable diode laser absorption spectrometer (TDLAS) 13/12, D/, 17/16, 18/16 2 2


GC prototype (Phobos Sample Return project)
capillary columns valves

calibration gas tank

carrier gas tanks

adsorption traps

TDLAS tube


TDLAS prototype (Phobos Sample Return project)
Name* Target molecule Sigma (cm-1) Lambda (nm)

C2H2 CO2iso

C2H2
18 18

6523.8794 cm-1

1533 nm

OC16O OC16O

4898.7822 cm-1 4899.5653 cm-1 4899.6133 cm-1

2041 nm

13CO 2

H2Oiso

HDO H H
2 2 17O 18O

3788.3366 cm-1 3788.7852 cm-1 3788.9125 cm-1

2640 nm

H2O-CO2

H2O CO
2

3727.7376 cm-1 3728.4101 cm-1

2682 nm

HDO HDO H216O H
2 17

O

H



Laser

= 2.64 m

2

18

O

H216O H216O