There is no legit way without Pokémon Ranger.
I am in the same boat. Presently I am hunting down United States Action Replay Codes for the Event Riolu that knows Aura Sphere from Pokemon Ranger Shadows Of Alma. I was unable to purchase the game, before the temporary missions for all of the above ceased. I have to trade or use cheat codes to get the Manaphy Egg, Darkrai from Pokemon Ranger Shadows Of Alma, and of course the ever popular Riolu that knows aura sphere from the same game.
If you use cheat codes you might need an action replay, or some other code device.
Good luck.
Aura sphere isn't a TM in Pokemon platinum.
You could look on "when does lucario learn aura sphere?" without the Pokemon Platinum in it, and that might be right. It says LVL. 36 I am so close to getting my Lucario to learn Aura Sphere! Also if you play WizArd101 pleez be my friend I am Gabriel ThunderStrider Initiate Theurgist!
sphere pillar.
Lucario learns Aura Sphere at lvl 42 in Pokémon Platinum
Riolu first has to evolve into Lucario in order to learn Aura Sphere. However, if you own Pokemon Ranger: Shadows of Almia you can download a special mission called Rescue the Kidnapped Riolu through wifi. After you complete the mission you are able to transfer a special Riolu that knows Aura Sphere to Pokemon Diamond, Pearl, or Platinum versions.
It is a event (its called the blue sphere and its also Pokemon Ranger Guardian Signs)
No you can't. I've allready cleared the game and there is no light sphere.
If you leave them long enough they will grow to larger sphere's the underground man should explain that.
IN POKEMON PLATINUM, MY LUCARIO HAD TO WAIT UNTIL LEVEL 37 TO LEARN AURA SPHERE. YOU MAY BE ABLE TO LEARN IT EARLIER IF YOU WAIT TO EVOLVE YOUR RIOLU =)
if it was Pokemon platinum dialege leans arua sphere at level 92
It can learn it but by tm. Buy it from the Veilstone department store.
A Prism Sphere can be found in the Underground tunnels in Pokemon Platinum. It is simply dug up in the walls of the tunnels using the explorer kit obtained in Eterna City. The sphere is clear and shaped like a prism, and it is harder to find than the red, blue and green spheres. It is thought to be symbolic of the Pokemon Diamond version since it resembles the structure on Dialga's neck.