Learner's definition of ASCERTAIN
to learn or find out (something, such as information or the truth)
They were unable to ascertain [=(more commonly) determine] the cause of the fire.
The police are now attempting to ascertain his whereabouts. [=to find out where he is]
Her doctors have been unable to ascertain [=find out] why she is ill. = Her doctors have been unable to ascertain the cause of her illness.
The information can be ascertained by anyone with a computer.