What two deserts lie on the tropic of capricorn

The Gibson Desert in Australia and the Atacama Desert of Chile lie in the Tropic of Capricorn. 
The Tropic of Capricorn is one of 5 major circles of latitude. It's the southernmost circle where the sun can shine directly, that is, it is the southernmost point or latitude from where the sun can be directly overhead. Its latitude is 23 ° 26'12.8 "and it moves constantly northwards. Its northern equivalent is the Tropic of Cancer.

I hope this information can help you.