I'm John Bachelors with my colleague and friend David Livingston, Dr. Space.

This is Hotel Mars.

Hotel Mars Venus version. We are happy to be speaking with two planetary

geologists, laboratory for atmospheric and space physics at the University of

Colorado Boulder, Aaron Kange and Beth and Gregory, two of the

authors of a new piece at Nature magazine, the peer-reviewed top, Venus Water

Loss is dominated by HCO plus, disassociative

rec combination which I now know to call D.R. But before I go any further

Bethan has made it very clear to me that while D.R. is important on Venus,

very important, it is only one of the ways that Mars lost its water.

Did I say that correctly Bethan? Yeah. Like,

so D.R. on Mars contributes to the loss of water but it's everything on Venus and

Aaron I come to you did the volcanoes come first contributing carbon dioxide to the

atmosphere 96% or did the water come first or simultaneously? How do we imagine it?

Yeah, and there's a little bit of uncertainty still about the history of the planets, but from

what we know, you can get a lot of water into a planetary atmosphere or the

surface so for example on early Venus due to volcanic activity which can bring it up

from the interior but it's also possible that some water was delivered via comets or

asteroids or really any sort of projectile that might have impacted Venus in its early days.

So there's sort of some supply from below and some supply from above.

David, you have a question for Aaron or Bethany?

I do again either one.

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