On the Possible Existence of Formaldehyde in the Atmosphere of Venus.

Abstract

view Abstract Citations (16) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS On the Possible Existence of Formaldehyde in the Atmosphere of Venus. Wildt, Rupert Abstract Ultraviolet spectrograms of Venus, and of the moon for comparison, were obtained with the long-focus quartz spectrograph (dispersion 21.7 A/mm at A 3300) attached to the 82-inch reflector of the McDonald Observatory, in order to search for the electronic absorption spectrum of formaldehyde gas, which might be formed in Venus' atmosphere by photochemical synthesis. The spectrograms revealed no sign of absorption by CH2O, while a mass of this gas equivalent to 3 mm-atm, under standard conditions, should have been sufficient for spectroscopic identification. This negative result does not refute the assumption that the photochemical formation of CH2O has played an important role in Venus' atmosphere during the past. In the light of Tarnmann's theory of the origin of the terrestrial oxygen, the lack of oxygen on Venus indicates that the primordial atmos- phere of this planet must have been extremely poor in water vapor. A tenuous atmos- phere of water vapor and carbon dioxide affords the very conditions for the photochemi- cal synthesis of formaldehyde, which appears to be capable of proceeding until the sup- ply of either of these gases has been exhausted. In a moist atmosphere CH2O rapidily polymerizes into a mixture of polyoxymethylene hydrates, (CH2O)~ H20, a white crystaffine solid. From laboratory data it is concluded that the amount of gaseous CH2O existing in equilibrium with the solid polymers is exceedingly small, which would seem to account for the failure of the spectroscopic test. The vapor tension of the solid polymers in the presumable range of Venus' atmospheric temperature is high enough to permit the dissolution and formation of clouds by processes of sublimation and sub- sequent condensation. As Venus' atmosphere is now spectroscopically free from water vapor but is obviously filled with clouds, the nature of which has never been settled, it is tentatively suggested that solid polyoxymethylene hydrates constitute the clouds shrouding the planet's surface Publication: The Astrophysical Journal Pub Date: September 1940 DOI: 10.1086/144214 Bibcode: 1940ApJ....92..247W full text sources ADS |