The term 'Ad ASTRA Per Aspera' is a Latin phrase which translates to 'To the stars through difficulties'. It is often used as a motto to express the idea that one must overcome obstacles in order to achieve success. The crossword solutions for this term are ASTRA, with 5 letters, and DIEM, with 4 letters. ASTRA is the Latin word for star, while DIEM is the Latin word for day. Together, these two words form the phrase 'Ad ASTRA Per Aspera', which can be interpreted as a reminder to strive for success despite any challenges that may arise.