Until the 20th Century it would have been virtually impossible to reach any sensible figure for the speed with which our galaxy-the Milky Way – is travelling through space. Many Scientists would not have presumed the galaxy to be moving at all.
This all changed, however, when the universe was shown to be expanding from a huge explosion or big bang of creation, with the Milky Way and the billions of other galaxies seemingly spreading out across the cosmos.
But how could we measure this speed of travel for our Milky Way? Scientists in the Forties had predicted that there should be residual evidence of the big bang in the shape of cosmic background radiation infiltrating the whole pf space.
When this was duly discovered in the Sixties it was used as the frame of reference with which to gauge the rate at which our own galaxy is spreading through the Universe. It turns out to be some 1.3 million miles per hour (2.1million km/hr)!