CREATE TABLE table_51893 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What is the score of the away team that played Essendon?
SELECT "Away team score" FROM table_51893 WHERE "Home team" = 'essendon'
SELECT "Away team score" FROM "table_51893" WHERE "Home team" = 'essendon'