Unfortunately, when an admin accidentally uses the “Delete” option to remove the student record, rather than the “Withdraw” option there is no way to restore grades automatically. When that happens, they must check mark a box that states “I understand this CANNOT BE UNDONE, not even from backups!”. So, unfortunately, that student record is lost now along with all his grades and attendance. You’ll have to re-enter it manually.
For future reference, we typically advise that it’s best never to delete any student records, unless it’s a fake record or an import mistake. There’s no harm is storing records in the data base. Teachers can and should run periodic backups of their grade books as insurance for incidents like this. They can do this on the Print > Grade books screen. Admins can also run periodic backups on the Setup > Import/Export screen > Export Grades/Rosters.
If you’d like to re-add the student in Jupiter, go to the Schedule > “Add/Drop Students” screen in Admin Mode > Re-enroll.