Does the Milky Way spin counter-clockwise? If so, do all spiral galaxies spin in this direction and why?
When I see depictions of the Milky Way it appears that the objects within it move counter-clockwise. Is this accurate? If so, do all spiral galaxies spin in this direction and why?
The direction that the Milky Way spins depends on your perspective. For example, take a top and spin it clockwise on a glass table. Then look at the spinning top from below the glass table - it will appear to spin counter-clockwise now. Or similarly, draw an arrow on a piece of paper in the clockwise direction, then hold the paper up to a light, looking at it from the bottom - now the arrow goes in the counter-clockwise direction. Thus the direction of the spin of any galaxy depends on your perspective when you look at it.
Scientists believe that on large scales the Universe is isotropic (the same in all directions). Thus, from our perspective, half of all spiral galaxies should spin clockwise, and half counter-clockwise. A recent analysis of the spin of spiral galaxies confirms this. The public classified over 35,000 spiral galaxies with spins both clockwise and counter-clockwise in the Sloan Digital Sky Survey as part of the Galaxy Zoo project. Scientists published the results in a recent paper and found that the Universe is indeed isotropic - we see the same number of clockwise as counter-clockwise spirals (within the uncertainties).
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist
This page has been accessed 30708 times since July 17, 2008.
Last modified: July 17, 2008 12:23:22 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)