>> David Harmon <b...@example.invalid> wrote:
>>> "Keith F. Lynch" <k...@KeithLynch.net> wrote,
>>>> There's no substitute for seeing or hearing something directly.
>>>> It's like the difference between attending a convention and
>>>> watching a video of the convention.
>>> Therefore, the best place to watch a lunar eclipse is from the
>>> moon.
Yes. It would look much more interesting from there.
On the other hand, 2014's transit of Earth from Jupiter won't look
like anything from Earth. Very sensitive space-based instruments
might be able to detect a slight dimming of Jupiter and its moons for
the duration. From Jupiter, it would look a lot like a transit of
Venus looks from Earth -- except that you could also see a transit
of Earth's moon. (Venus has no moon.) And except that it's always
cloudy on Jupiter, so you couldn't actually see anything at all.
You could see it from some of Jupiter's moons, however.
>>> If you watch a lunar eclipse from the moon, is it still called a
>>> lunar eclipse, or something else?
>> No, it would be a solar eclipse by the earth.
Right. Earth would appear as a spectacular luminous orangish ring
with lots of subtle and changing gradations of color, as you saw all
of Earth's sunsets and sunrises simultaneously. The ring would look
completely dark inside, as no cities are bright enough to be seen from
the Moon.
> Well, sure, unless someone comes up with something more colorful.
> What is the adjective for "by the earth" ?
"Terrestrial."
> They could just call it a solar eclipse and let confusion reign.
Earth's shadow, like the Moon's shadow, is always *somewhere*. In a
sense there has only ever been one solar eclipse (by the Moon) and
it's lasted billions of years. It's just that it seldom lands on
Earth. Similarly with Earth's shadow and the Moon -- or Jupiter. Of
course it's called a transit, not an eclipse, if it doesn't block all
of the sun. Unless it's called an annular eclipse instead.
The on-again off-again James Webb Space Telescope will -- if it isn't
canceled -- be located where there's a perpetual transit of Earth.
But it will be facing the other way. The idea is to situate it where
all signigicant nearby sources of unwanted heat and light -- The sun,
Moon, and Earth -- are always behind it.