Originally posted by Earthscum
Taibak: Actually, a cluster of asteroids isn't impossible, or even improbable. All you need is one large asteroid/meteorite with enough mass to have
a significant gravitational effect on smaller ones. I believe they have found small clusters before, but not too sure... been about 2 years since I
even researched any of that.
Problem is the larger rock would have to be planet sized to have that much gravity. That takes us back to a big, easy to spot object.
As for the clusters we have seen, the only asteroid I know of that has a satellite is Ida. Its satellite, Dactyl, is only about 1.6 km across -
incredibly tiny - and orbits at about 100 km. If Ida were to have more rocks bound to it, they would either be close enough to bounce off each other,
which could easily disrupt their orbits, or they'd be far enough to be bound only weakly. Either way, if the cluster were to pass close enough to
one of the gas giants, the cluster would be broken up, at least in part, by the planet's *much* larger gravity. Or, consider the possibility that
such a loosely bound cluster would have been ripped apart by the Sun's *huge* gravity.
Dactyl aside, the only other clusters of asteroids that I know of are not gravitationally bound to each other. Instead, they're merely herded
together by being 'pushed' at regular, repeated intervals by the gravity of a much larger object - Jupiter for the asteroid belt and Neptune for the
Kuiper Belt. The gravity of the asteroids/Kuiper Belt objects is negligible.
Not really sure how fast it would have to travel, really... just speculating. I believe that Nibiru was in the sky for several generations, if
I'm not mistaken. Not really sure.
In which case, how did the ancient Europeans, Chinese, Russians, Indians, Egyptians, Cambodians, Mesoamericans, South Americans, Amerindians,
Australians, and Polynesians miss it? It's more than a little suspiscious that the *only* people who supposedly saw this honkin' bright object were
the Sumerians. And even then, that theory rests solely on the work of Zacharia Stichin, whose translation is laughable - at one point he even misses
the difference between carbohydrates (bread) and hydrocarbons (kerosene)!
About filters: you can actually be safe with 2 lenses used for arc or TIG welding stacked, but you need to limit the amount of time you expose
your eyes to even the filtered light.
A number 16 welding filter will do the trick. If you want to go this route, do *NOT* settle for a lower number - if you do, the filters will not
block the infrared light and your eyes will be burnt to a crisp.
If you have a telescope, you can most likely just purchase a sun filter pretty cheap.
Celestron's runs about $60 for a filter designed to fit a 5" Newtonian.
(Edited once to fix a typo)
[Edited on 28-3-2004 by Taibak]