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Q&A: Dark Matter
Q:
Regarding the Dark Matter Mystery. Did the equation for the mass
of the galaxy include planetary zones for the stars? Just
looking at our own solar system, a large proportion of the mass
seems to be in the planetary zone and made up of elements with
much greater mass than just hydrogen. Also these planets and
debris fields probably wouldn't emit much in the way of radio
energy and if planets existed in sufficient numbers would
increase the mass of the galaxy by quite a lot.
A:
The mass of all the planets in our solar system is about 0.1
percent of mass of the Sun, so if our solar system is typical,
the total mass of planets in the galaxy is small compared to
that of stars.