# Combined speed of Earth in Space is 1.5 million mph - how much slower is time for Earthlings as a result?

Theres a problem for intergalactic astronauts which is finding their way back to Earth. Combining all the rotational speeds, we are spinning and orbiting the sun, in our solar system which is spinning in the Milky Way, which is spinning in a large cluster, which in turn spins in a super cluster. Combining all the speed of the rotational forces equals 1.5 million mph. Said Intergalactic Astronaut would have a job to find where the Earth is if they flew into space and out of the super cluster. But my question is this, the astronaut HAS managed to find a ship to leave the Earth, the solar system, the Milky Way, the Large cluster, the Super cluster and is at relative to us, is motionless in space, observing us. How much faster is time for the astronaut? Or how much slower is time for us on Earth, given the speed of Earth and gravitational effect on time.

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1.5M miles/hr relative to what exactly? There is no such thing as absolute speed. Every speed is relative to something. – Pranav Hosangadi Dec 2 '13 at 19:34
There is no such thing as "motionless in space" without a reference. Motionless compared to what? – Olin Lathrop Dec 2 '13 at 20:52