Pacalin

Description: Neil deGrasse Tyson and Carl Sagan.

Description: Three astronomers who changed our understanding of the stars. Henrietta Swan Leavitt developed a system for measuring distances in the cosmos by tracking the luminosity of stars. Annie Jump Cannon classified hundreds of thousands of stars, and her system is still in use today. Cecilia Payne found the temperature scale of stars by understanding the abundances of hydrogen and helium in them, and her 'Stellar Atmospheres' is widely acknowledged as the most brilliant Ph.D. thesis ever written in astronomy.

Description: Two of our beloved space advocates, advocating planetary science. :)

Description: Let's go to Mars, guys!

Description: Bioshock for NES.

Description: Science is true whether or not you believe in it. ~NdGT

Description: Commissions for this shirt go to The Planetary Society.

Description: Invading the grid.

Description: Reminiscing in the park.

Description: A glitch in the Tetrix.