NASA A Weekend with Chris McKay: NASA Scientist

[Simfish]

http://spacescience.arc.nasa.gov/staff/chris-mckay

We're spending a weekend with him (as part of a summer program)

 

[MACHO-WIMP]

I have a bunch of questions since I'm not so familiar with this field. I'm jealous that you get to spend the weekend with him!

 

[Drakkith]

I don't know enough about the subject to come up with a good question lol.

 

[Chronos]

OK, I 'll bite. What atmospheric chemical signatures might suggest something akin to biological activity on an exoplanet? In other words, What reactive compounds, such as free atmospheric oxygen, would be difficult to explain without replensishment by something resembling biological contributions?

 

[tony873004]

I got to spend a few days with Chris McKay at Zzyzx in the Mojave Desert with the Spaceward Bound group twice in the last 3 years. You'll love him. He's very approachable. I remember somebody asked him how sunscreen works. Yep, he knows that too!

Ask him about the newly-discovered running water on Mars.

 

[Simfish]

Okay - replies will come a bit slow since there isn't much free time on vacation. But I'll say these things

OK, I 'll bite. What atmospheric chemical signatures might suggest something akin to biological activity on an exoplanet? In other words, What reactive compounds, such as free atmospheric oxygen, would be difficult to explain without replensishment by something resembling biological contributions?

Ah - so he's more interested in Mars/Europa/Titan than he is about exoplanets (since he wants to directly determine whether or not exolife exists - which can really only happen with missions to these three bodies). That being said, he says that the vertical temperature distribution of hydrogen gas (H2) on Titan (far less of it at the surface than you would expect) is such that it's difficult to give an abiotic explanation of it (right now)

What reactive compounds, such as free atmospheric oxygen, would be difficult to explain without replensishment by something resembling biological contributions?

Free atmospheric oxygen, ozone (related to oxygen), methane (might be others)

I got to spend a few days with Chris McKay at Zzyzx in the Mojave Desert with the Spaceward Bound group twice in the last 3 years. You'll love him. He's very approachable. I remember somebody asked him how sunscreen works. Yep, he knows that too!

Hahaha nice. :) I wonder how he responded to how sunscreen works. He's really good at making deadpan jokes

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As for the newly-discovered running water - I'll ask tomorrow. I do know that a lot of it may depend on the biological impact of salts other than sodium chloride (which we know next to nothing about right now). The Phoenix lander showed a huge overabundance of perchlorate salts at its landing site (which is what has become his new obsession), and he's trying to figure out the implications of that right now.

 

[Greg Bernhardt]

Thanks Simfish!