The Andromeda galaxy is hurtling towards us at 250,000 mph, in relation to what? Speed here on earth is generally measured in relation to the surface, assuming it to be stationary. In space, nothing is stationary, nothing is upside down etc. If you're traveling in space and you meet another traveler going the opposite direction, and after you meet you recede from each other at a speed of lets say 5kmh. You have no idea really if you're both going 2.5kmh, you're stationary and he's travelling at 5kmh, or your floating along at 50 kmh and he's going 55 kmh.. So back to my example Andromeda - is the 250,000 mph in relation to the Milky Way? Since our galaxy is also hurtling through space, are we traveling in the same direction and Andromeda is just catching up, or are the two galaxies actually moving towards each other? If all celestial objects are getting further away from each other would I be correct in assuming Andromeda is "catching up"? If everything in space is moving, there is no real reference point, and if Andromeda is moving towards us at this speed, I'm assuming that speed is calculated with the assumption our galaxy is standing still (even thought it isn't) much like how we calculate speed here with the assumption the surface is standing still..