There IS a difference with California emission and Federal (49-State) emission requirements. However if this Saturn is equipped with the Federal required emission components which it was originally equipped with, it can pass the California smog check and be registered with the CA DMV. you will have 30 days after moving to California to get a smog check and complete the registration process. Assuming this Saturn has be well maintained it should not have a problem passing the California emissions test.
The rule is any USED vehicle which is equipped with the necessary Federal Emission Components is eligible for California registration as long as the vehicle's exhaust emissions fall within California's limits and the vehicle's emission system has not been tampered with.