VARCHAR2 to DATE Conversion Error

select to_char(to_date('August 10th 2002', 'Month DDth YYYY'), 'DD-MON-YYYY')
from dual

returns

ERROR at line 1:
ORA-01841: (full) year must be between -4713 and +9999, and not be 0

Uhhh???? Received on Fri Aug 09 2002 - 04:52:46 CDT