Re: oppositions
When Mars is at its perihelion and the Earth at its aphelion and Mars is in <ahref=http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970217a.html>opposition, it happens every 15 years.
But it's hardly ever perfect; there could be several days difference; I also read somewhere that the 2003 opposition will be unusually close.
Unfortunately, Mars will again be low above the horizon for northerners and Mars will once again go through a huge storm at that time.
Raoul