Could Rogue Planets be an Alternative to Dark Matter?

[lalbatros]

Hello,

I learned from Yahoo about the existence of many more "rogue planets" than stars.
These planets are not bound to a solar system, they are "free floating".
I found more information on wikipedia and jpl.

I wonder now if these "rogue planets" could be an alternative to the "dark matter" to reconcile the various data on galaxies.

Would you have some ideas or some data about this?

Thanks,

Michel



http://news.yahoo.com/s/space/20110518/sc_space/lonelyrogueworldssurprisinglyoutnumberplanetswithsuns
http://en.wikipedia.org/wiki/Rogue_planet
http://www.jpl.nasa.gov/news/news.cfm?release=2011-147

 

[twofish-quant]

I wonder now if these "rogue planets" could be an alternative to the "dark matter" to reconcile the various data on galaxies.

Nope. The problem with rogue planets is that there aren't enough of them to account for dark matter. A lot of the work looking for rogue planets comes from work trying to use them as an explanation for dark matter, and there aren't enough of them.

From memory, you need about a thousand times more rogue planets for them to make a reasonable candidate for dark matter.

Would you have some ideas or some data about this?

Look up MACHO.

 

[phyzguy]

Also, both the data from BBN (Big Bang Nucleosynthesis) and the data from the CMB (Cosmic Microwave Background) tells us that the dark matter can't be composed of baryons. so dark matter can't be made of atoms - it's something else.

 

[twofish-quant]

Also, both the data from BBN (Big Bang Nucleosynthesis) and the data from the CMB (Cosmic Microwave Background) tells us that the dark matter can't be composed of baryons. so dark matter can't be made of atoms - it's something else.

Also there are different "levels" of dark matter.

If you take the estimated amount of "ordinary matter" from BBN and CMB, and the add up all of the matter that we can see, you find that we only see a small fraction of the ordinary matter out there.