Saul Levy wrote:
By the time an asteroid (usually dark) becomes visible in the day sky,
it will be too late.

Saul Levy



The only difference (tho significant) is that a "comet" most likely consists
of "ice" while an asteroid (light or dark) most likely consists of metal or
stone...

Correct me if I'm wrong: but, Any body --ice, metal or stone, as it approaches
the sun --will begin to melt and emit a trail of 'gas;' the ice body sooner,
with a larger 'tail' of course.

But, for an asteroid (dark body or light) to be visible in the day time does
not mean it will hit the earth--it could be visible because it is nearing the sun.

Certainly if it is visible because it is falling into our atmosphere then it
has already hit. duh ;-)



As for this asteroid "ALH2804-C"...? ?