Utapu is a planet with many craters which the inhabitents like in. Utapu is also the locaton which General Grevious, the leader of the Separatist movement moves to avoid capture by the Jedi Council. The planet Utapu as being the Separatists location is revealed to Anakin Skywalker by Emperor Palpatine who says his spies found out their location. Vice Chancellor Palpatine orders Anakin Skywalker to face General Grevious on the planet but Palpatines orders are overruled by Mace Windu who sends Obi-Wan instead.
On Utapu, during the final fight between General Grievous and Obi-Wan Kenobi, the latter uses a gun for a rare shot. Once General Grevious has been killed, it is believed that the Clone Wars would now come to an end. On hearing of Grevious`s death, Palpatine orders Order 66 which orders his Stormtroopers to turn on the Jedis and kill them all. Obi-wan manages to avoid being killed by Clone Troopers and manages to get off the planet and to Polis Massa where he discusses with Yoda and Bail Organa on the next step of what to do. The Old Republic has been crushed and now is the time to regroup.