Speed of revolution of milkyway galaxy?

Answer 1

We can't really say, as we have to point of reference to be moving from. There are calculations on the order of 570 kilometers per second, but these are meaningless without a fixed reference.

The furthest galaxies we can see are moving at a high percentage of the speed of light relative to us, so we're moving that fast from their perspective.

Answer 2

The Milky Way is a barred spiral galaxy that looks much like a pinwheel, and just like a pinwheel our galaxy is spinning. Stars in the arms of the galaxy are orbiting about the center, and the entire disk of stars, gas and dust is rotating at approximately 270 kilometers per second (168 miles/second), which translates to 970,000 kilometers/hr ( 600,000 miles per hour).

This rate of rotation means that the Solar System - which is 28,000 light years from the center of the Milky Way - completely orbits the galaxy about every 225 million years. The last time we were in the same place in our orbit, dinosaurs were just starting to appear on the Earth.

Viewed from "above" - what would be North on Earth - the Milky Way spins in the counter-clockwise direction. Of course, if you were to view it from the other side, it would spin clockwise.

Answer 3

It doesn't make a lot of sense to think this way. The Milky Way isn't a rigid disc, but consider for a moment a record or CD spinning... the outer edge has to travel a lot faster than the inner edge. Where, exactly, should you measure it to determine the speed in miles per hour?

If you mean "About how fast is the Sun moving around the Galactic Center", that's a little easier. Using a distance to the GC of 26,400 light years and a rotational period of about 250 million years, my quick back-of-the-envelope calculation comes up with around 450,000 miles per hour. However, we're not exactly sure of either the precise distance or the exact period, so that number could be off by a bit... I'd say 300,000 to 600,000 miles per hour is a reasonable bounding box for the value.

Answer 4

The Milky Way does not rotate as a unit; the individual stars in it orbit the barycenter at different rates.

Also, we don't know exactly, we haven't been making detailed observations for long enough, but we think the Sun takes somewhere between 200 and 250 million years to make a complete circuit.

Answer 5

Galaxies spin differentially - that is, they don't spin as a solid object would. The speed of the revolution of individual parts (stars, etc.) is given by the laws of cellestial mechanics. As an example, the Sun (or the Solar System) orbits the center of the Milky Way at a speed of about 220 km/second. At that speed, it takes the Sun about 240 million years for one orbit. If any star were to move around much faster than that (say, 2 or 3 times as fast), it would probably escape the Milky Way. In the case of a more massive galaxy (more specifically, more mass concentrated in the same space), objects could orbit the center of the galaxy a bit faster than that.

Answer 6

Approximately 230 km per second.

See related question

Answer 7

1,826 miles per second

Answer 8

very fast