Re: Is possible to use LASER for comet deflection?

    Clearly comet deflection by LASER can not be done with current 
technology. We are still trying to understand LASER technology through 
the mirrors left on the moon's surface, understand the light waves that 
are produced and the distance they can travel. 
    If it were possible, the LASER would almost certainly have to be 
space based or it would end up doing a great job ionizing the 
atmosphere above it. Thus the idea, by President Bush, to create the moon 
to be station for further space exploration. The moon would be a great 
place to put the LASER, if it were indeed possible.
    The power of the LASER, however, would have to be enormous. That can 
be bounded by assuming 100% efficiency (i.e. all the laser energy goes 
into the vaporized jet and none into merely heating the comet body) and 
using some reasonable numbers for comet masses, and then adding a bit of 
celestial mechanics, and then trying to figure out just how much the 
laser beam spreads (a significant practical limitation over the 
distances likely to be involved).