Penelope Boston

Speleologist; Associate Director of the National Cave and Karst Research Institute

Jill Tarter

Astronomer & Bernard M. Oliver Chair for SETI Research at the SETI Institute; Recognized for Work on Extraterrestrial Intelligence

Dr. Phil Plait

Blogger for Discover Magazine at Bad Astronomy, where he deconstructs misconceptions and explores the wonder of the Universe.

Carolyn Porco

Planetary Scientist Known for her Work in the Exploration of the Outer Solar System

John Holdren

Professor of Environmental Policy & Director of the Program on Science, Technology, and Public Policy at the Harvard Kennedy School of Government

Bobak Ferdowsi

NASA's Jet Propulsion Labs Flight Director; Curiosity Rover Landing

Anil Ananthaswamy

Award-Winning Science Writer & Author of "The Edge of Physics"

Kevin Hand

Planetary scientist/ astrobiologist

Eric Berlow

Data Ecologist, Complexity Scientist

Ellen Stofan

Under Secretary for Science & Research at the Smithsonian; Former Chief Scientist at NASA

Fiorenzo Omenetto

Professor of Biomedical Engineering; Physicist

Ginger Zee

Chief Meteorologist for ABC News, Author & Mental Health Advocate

Chasing Helicity: Through the Storm (The Chasing Helicity Series) (Chasing Helicity Ser...

Andy Weir

Science Fiction Author, Known for "The Martian"

Molly Crockett

Globetrotting Neuroscientist investigating altruism, morality and economic decision-making.

Peter Girguis

Associate Professor of Natural Sciences at Harvard; Adjunct Research Engineer at the Monterey Bay Aquarium Research Institute

Laurence Bergreen

Award-winning Biographer, Historian and Author of "Columbus: The Four Voyages" and "Over the Edge of the World: Magellan's Terrifying Circumnavigation of the Globe"

Bart Knols

Scientist, Author, Entrepreneur

Dr. Hendrik Poinar

Evolutionary Biologist Specializing in Ancient DNA

Mario Livio

Renowned Astrophysicist, Lecturer, and Best-selling Author

Garrett Reisman

Astronaut, Professor of Astronautical Engineering at USC & Senior Advisor at SpaceX