Re: Sky People's solar system
|From:||Padraic Brown <pbrown@...>|
|Date:||Wednesday, January 20, 1999, 18:51|
On Wed, 20 Jan 1999, Christophe Grandsire wrote:
> >> - a double planet, the bigger the size of Mars, the smaller just
> >> slightly smaller. No atmosphere (to close to the sun), but visible.
> >Don't be too quick to assume that nearness to the star = no atmosphere.
> >Mercury has a sodium-helium-hydrogen atmosphere. Thin to be sure, but
> Is it really an atmosphere or some gas rejected by the sun and captured by
> the gravity of Mercury? I mean, if its composition keeps stable whatever
> the activity of the sun, it's an atmosphere. If not, I can't name it an
It's a combination: the H and He are thought to have been captured from
solar ejections; the Na is from Mercury itself. Regardless of how it gets
there, it's there and forms, for lack of a better term, an atmosphere.
I can't speak to the solar activity bit. But even here on Earth, varying
solar activity affects the upper layers of the atmosphere. And I'm sure
at least _some_ of our atmosphere is derived from captured solar material.
> >> - a solitary little rock and icy planet, maybe an ex-moon of the
> >> planet (very possible as its orbit cuts the orbit of this planet). It has a
> >> small volcanic activity, hence a light atmosphere. No moon.
Perhaps the Sky Peoples' astronomers will come to intellectual fisticuffs
over the proper nomenclature of this planet, as ours are over Pluto.
There's apparently a camp that wishes to reclassify Pluto as either a
Minor Planet or an asteroid. Hm. An Asteroid Belt with one asteroid in.
Well, two if we count Charon.
> I'll think of it, but I think I'll add one. Comets are so beautiful!
Especially when they hit something! ;^) Plus the added benefit of a
continual supply of "new" water for the planet.
> Thank you for your information. It will be very useful.
You're most welcome.
> Christophe Grandsire