Venus Was Wet: A Measurement of the Ratio of Deuterium to Hydrogen

  title={Venus Was Wet: A Measurement of the Ratio of Deuterium to Hydrogen},
  author={Thomas M. Donahue and John H. Hoffman and R. Richard Hodges and Andrew J. Watson},
  pages={630 - 633}
The deuterium-hydrogen abundance ratio in the Venus atmosphere was measured while the inlets to the Pioneer Venus large probe mass spectrometer were coated with sulfuric acid from Venus' clouds. The ratio is (1.6 � 0.2) x 10–2. The hundredfold enrichment of deuterium means that at least 0.3 percent of a terrestrial ocean was outgassed on Venus, but is consistent with a much greater production. 

Was Venus Wet? Deuterium Reconsidered

The ratio of deuterium to hydrogen on Venus has been accepted as proof of a wetter, more Earth-like past on that planet, but an alternative interpretation of the D/H ratio is offered, in which the measured value is consistent with a steady-state evolution over the age of the solar system.

Deuterium on Venus: Observations From Earth

The resulting value of the deuterium-to-hydrogen ratio (D/H) is 120 � 40 times the telluric ratio, providing unequivocal confirmation of in situ Pioneer Venus mass spectrometer measurements that were in apparent conflict with an upper limit set from International Ultraviolet Explorer spectra.

Venus methane and water

The Pioneer Venus Large Probe Neutral Mass Spectrometer collected data that apparently, but almost surely misleadingly, indicate the presence of a large amount of methane (1000- 6000 ppm) in the

Deuterium in the solar system

Values of D/H measured in the methane on the giant planets and Titan indicate the presence of two distinct reservoirs of deuterium in the outer solar system. The dominant reservoir is in hydrogen

Identification of deuterium ions in the ionosphere of Venus

The dominant mass 2 ion in the ionosphere of Venus is identified as D+ through analysis of the height variation of [mass 2 ion]/[H+] measured in the chemical equilibrium region by the ion mass

Deuterium content of the Venus atmosphere

THERE is no liquid water on Venus. The water vapour in its atmosphere would, if condensed, form a layer only 20 cm deep which means, in contrast to the 3-km-deep oceans that cover its sister planet

Past and present water budget of Venus

A detailed analysis of Pioneer Venus large-probe neutral mass spectrometer (LNMS) data confirms an earlier report that the abundance of Venus deuterium relative to hydrogen is 2 orders of magnitude

First optical detection of atomic deuterium in the upper atmosphere from Spacelab 1

Measurements of the deuterium-to-hydrogen ratios (D/H) in the fields of meteorology1,2, tropospheric3,4 and stratospheric chemistry5,6, planetology7,8 and cosmogony8,9 have previously been performed



The ratio of deuterium to hydrogen in the Venus atmosphere

Interpretations of the Lyman-α data from Mariner 5 are critically discussed, in view of the finding by the experimenters that a normal exosphere of atomic hydrogen does not fit. A two-component

Composition of the Venus lower atmosphere from the Pioneer Venus Mass Spectrometer

Data from the Pioneer Venus sounder probe neutral mass spectrometer confirm that the major constituents of the lower atmosphere of Venus are CO2 and N2, with the latter having a mass abundance of

Escape of Hydrogen from Venus

It is suggested that the mass-2 ion observed by Pioneer Venus is D+, which implies a ratio of deuterium to hydrogen in the contemporary atmosphere of about 10–2, an initial ratio of 5 x 10–5 and an original H2O abundance not less than 800 grams per square centimeter.

Measurements of the Venus lower atmosphere composition: A comparison of results

From the Pioneer Venus, as well as the Venera 11 and 12 spacecrafts, data on the chemical composition of the Venus atmosphere from about 700 km to the surface were obtained. In general, reasonable


The absolute isotopic ratios of the hydrogen content of two reference water standards called “SMOW” 2 and “SLAP 3 were measured to define an absolute isotopic scale. This isotopic scale can be used

The Upper Atmosphere of Venus: A Review

Abstract The implications of recent data on Venus obtained by Mariner 5, Venera 4 and ground based observations for the aeronomy of Venus is received. The theoretical thermal structure model of

Interpretation of the Mariner 5 Lyman alpha measurements.

  • C. Barth
  • Physics, Environmental Science
  • 1968
Abstract The Mariner 5 Lyman alpha measurements can be fitted with the barometric-exospheric equation only if a two-component model atmosphere is used. Of the three possible hypotheses to explain

An estimate of the present-day deep-mantle degassing rate from data on the atmosphere of Venus

We argue that the present rate of escape of hydrogen from the upper atmosphere of Venus establishes an upper limit for the rate of degassing of water from the interior of the planet. This upper limit

The Runaway Greenhouse: A History of Water on Venus

Radiative-convective equilibrium models of planetary atmospheres are discussed for the case when the infrared opacity is due to a vapor in equilibrium with its liquid or solid phase. For a grey gas,

Capture of Phobos and Deimos by photoatmospheric drag