Stanford University http://solar-center.stanford.edu/FAQ/Qsolsysspeed.html http://solar-center.stanford.edu/FAQ/Qsolsysspeed.html Stanford University 200 kilometres a second http://solar-center.stanford.edu/FAQ/Qsolsysspeed.html http://solar-center.stanford.edu/FAQ/Qsolsysspeed.html 200 kilometres a second http://solar-center.stanford.edu/FAQ/Qsolsysspeed.html Stanford at 40,000 miles an hour Sun