Hoth contains 5 datacrons, 4 of which can be done solo, and 1 of which.... well it's tough. The datacron run here tends to be on the lengthy side, though they're quite interesting.
With the exception of the starter planets, Quesh is the only planet with 3 datacrons. All can technically be solo'ed, though getting to 1 in particular can cause a problem. By problem, I mean death.
Finally, a break from hard-to-obtain datacrons! Balmorra's 5 datacrons are all relatively easy to obtain. One requires a vendor item, but even that one is easy to grab.
Only 4 of Alderaan's datacrons can be solo'ed while levelling, with the 5th either requiring you to have outlevelled the planet, or have brought 2-3 friends. This is also the first planet where you must buy items from a specific vendor to obtain certain datacrons.
Tatooine is known for the evil 40 minute "blimp ride". It's also known for the "death run" that Republic players need to make through an Imperial town to get to another datacron. Peaked your interest yet?
Nar Shaddaa's 5 datacrons can be solo'ed, but are
notable for 2 reasons:
(1) It's the first time we see +3 to a stat.
(2) They are some of the most challenging to obtain.
Taris contains 5 datacrons. Most involve a lot of walking, though this is the first time you come across a datacron that actually requires 2 people & a little teamwork! The other 4 can be solo'ed.