Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_30057479_1 (researched_at VARCHAR, geometry VARCHAR)
### Question:
Where was d: ~50nm, l: ~600nm geometry researched?
### Answer:
SELECT researched_at FROM table_30057479_1 WHERE geometry = "D: ~50nm, L: ~600nm"