The planet Mercury will pass close to the bright star Spica in Virgo. This is a particularly good apparition of Mercury for observers in the Southern Hemisphere, less so for northerners.

Car-free day encourages motorists to refrain from using their car for a day.  Most cities have their own websites for car-free day – here is one for the world.

The sun crosses the celestial equator moving southward. Day and Night are of equal length. The sun rises due east and sets due west everywhere on Earth. This is the autumnal equinox in the Northern Hemisphere, the vernal equinox (Spring) in the Southern Hemisphere.

World Environmental Health Day addresses environmental health inequalities. While environmental health may be concerned primarily with the impacts of environmental stressors on health, these in turn are heavily influenced by and frequently reflect economic and social factors.