External back-up failed

The OS reported this morning that it hadn't backed up my HD for 10 days!
Further investigation shows that my Maxtor 1 TB external drive is no
longer recognised by the OS.
Touching the outer casing of the unit I can feel vibration from within
and I guess that the disk must be spinning inside.

Is this disk failure do you think? The unit is getting on for 5 years
of age, and failure wouldn't be unexpected at this age.

Any recommendations for a replacement?

Peter

--
It is necessary for the good man to do nothing for evil to triumph.

Attributed to Edmund Burke 1729 - 1797
.