How does Venus 's atmosphere compare to Earth 's ?
Nevertheless , assuming that early Venus 's H2O had a D / H ratio similar to Earth 's Vienna Standard Mean Ocean Water ( VSMOW ) of 1.6x10-4 , the current D / H isotopic ratio in the Venusian atmosphere of 1.9x10-2 , at nearly x120 of Earth 's , may indicate that Venus had a much larger H2O inventory .