It gets really close in August 2003 - only 35m miles away compared with its average distance of 49m miles. The last time it was this close was in 1986. The best place to see it in 2003 in near the equator, but the view will be good enough in the UK for most people.
This year (on June 13) it gets close enough - 43m miles - for its polar ice caps and clouds to be seen through a small telescope. You'll see it with the naked eye as a bright red light in the night sky.