[ExI] SETI reviews the Drake equation
johnkclark at gmail.com
Tue Feb 5 00:29:58 UTC 2019
On Mon, Feb 4, 2019 at 12:51 PM Stuart LaForge <avant at sollegro.com> wrote:
> And this is where Sgr A*, the 4 million solar-mass black hole at the
> center of our galaxy comes into play:
The Milky Way may be an oddball for a spiral galaxy of its size, the
Andromeda spiral galaxy is only about twice the size of ours but it has not
one but two black holes at its center; the smaller one is of 40 million
solar masses, ten times the mass of our galaxy's black hole and the larger
one is between 110 and 230 million solar masses.
And it's a elliptical galaxy not a spiral like ours but M-87 has a 3.5
billion solar mass black hole at its center. We don't seem to to be living
in a typical solar system as it has no hot Jupiter or a super Earth in it and
they are 2 of the most common type of planets; perhaps we don't even live
in a typical galaxy.
John K Clark
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