You need to filter on the join if selecting only specific records in the left join.
I.e.
Select a.*, b.*
From a
left join b on a.id = b.id
and b.date >= '06-01-2011'
where a.name = 'smith'
Another option is to use a CTE to filter the data first for the saturn.shrtgpa table and then left join to the CTE instead.