What was the original air date for the episode Calle, The Transit of Venus? 
CREATE TABLE table_19517621_4 (original_airdate VARCHAR, title VARCHAR)
SELECT original_airdate FROM table_19517621_4 WHERE title = "The Transit of Venus"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_19517621_4 (original_airdate VARCHAR, title VARCHAR) Question: What was the original air date for the episode Calle, The Transit of Venus?  [/INST] SELECT original_airdate FROM table_19517621_4 WHERE title = "The Transit of Venus" </s>