Re: superhero space navigation

On 7 apr, 18:44, Andrew Plotkin <erkyr...@[EMAIL PROTECTED]
> wrote:
> Here, Bryan Derksen <bryan.derk...@[EMAIL PROTECTED]
> wrote:
>
> > Andrew Plotkin wrote:
> > > You mentioned a cluttered sky, but remember that it's cluttered
> > > because everything is brighter. Planets are brighter too. If you're
> > > inside Earth's orbit, the brightest things visible (after the Sun)
> > > will be Venus, Earth, Mars, Jupiter, and maybe Mercury. The Sun's
> > > position against the stars (plus your printout) will tell you
> > > immediately which of those planets might be behind the Sun (or lost
in
> > > its glare).
>
> > You'll probably be able to distinguish which planet is which by their
> > appearance, especially if you've got a modest telescope. Mars is the
> > reddish one, Venus is the brightest one, Jupiter is the one with four
> > moons, Earth is the bluish one with one moon, and Mercury is
whatever's
> > left over near to the sun.
>
> I've never been able to see planetary colors naked-eye (even for
> Mars), so I distrust this. :) I realize it'll be a lot easier above
> the atmosphere, and more so with binoculars.
>
> As for brightnesses, that does depend somewhat on distance -- Earth
> close up might be as bright as Venus farther out. And the Moon might
> not be visibly different from a star; it's smaller and lower-albedo
> than the Earth.
>
> Not saying those aren't helpful. I just want to make sure I can get
> around without those clues.
>
Yes, but the Moon is just 4 magnitudes dimmer than Earth Unlike the
satellites of Jupiter or of Mars. If a planet suspected for Earth is
in view, just check for another star which is about 4 magnitudes
dimmer and also does not belong in the constellation