If samples can be collected from the surface, for example, scientists might find rocks that formed when the planet was wet, Grinspoon said.
Determining how much water remains locked in these rocks may allow scientists to figure out how long ago the planet dried out.
Similarly, studies of Venusian gases could help scientists better estimate the rate at which water was lost into space.
Already such research is playing a role in our understanding of Venusian heating.
At the Orlando meeting, French researcher Jean-Loup Bertaux reported that the Venus Express spacecraft, now orbiting the planet, has discovered a rare form of carbon dioxide never before detected on Venus.
Instead of containing the most common form of oxygen, which has eight protons and eight neutrons, this one has one atom of oxygen with eight protons and ten neutrons.
That causes it to absorb more infrared light than normal carbon dioxide, increasing its strength as a greenhouse gas.
The upsurge of interest in Venus comes hard on the heels of a recent finding that early Mars might have been colder and drier—and therefore less habitable—than previously believed.
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