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Lucianne Walkowicz is the Henry Norris Russell Fellow in the Department of Astrophysical Sciences at Princeton, and a 2012 TED Senior Fellow.
Lucianne's profile on TED: http://www.ted.com/speakers/lucianne_walkowicz.html
Lucianne's blog: http://tangledfields.com/
Questions answered in this episode:
1. If we were to add a lot of mass to the moon, for its gravity to get stronger, what would that mean to the rotation of the earth? —Barrows0re
2. If smaller objects are being pulled by larger objects, then why does the moon get further and further away from earth? —Draftgon
3. Why are celestial bodies always spherical in shape? i.e stars, planets, moons. —Az A