Finding a Comet Igniter for Tian Wen in Arc Raiders' Collision Course quest is simple if you know the trick to getting them. If you don't, or you haven't encountered this Arc enemy much, then it's much more of a bother.
These exploding balls always seem to catch me at the most inopportune moment and send me running for the hills so as not to get vaporised by their huge shockwave. That said, here's how to get this item and destroy a Comet for Tian Wen.
Destroy a Comet and deliver a Comet Igniter to Tian Wen
While you can find Comets on just about every map, there are loads patrolling the beach on the new Riven Tides map. These Arc look a little like Fireballs or Pops, except they're larger, more similar to a Surveyor—essentially, they're a big metal ball with a blue light on the front that will turn yellow if they spot you.
When they decide to murder you, they'll roll in your direction before blowing up. The thing is: you have to kill a Comet before it blows up to get its Comet Igniter. Doing so will spawn a separate loot container that looks a little like a core as opposed to the usual ring. Loot this and you'll find a Comet Igniter inside. The best and cheapest way I've found to quickly kill a Comet before it blows up is using Seeker Grenades and Snap Blasts.
It only takes a few of these grenades and you can buy them from Apollo daily. I especially like the Seekers as they track to enemies. As long as the Comet hasn't spotted you, you'll have plenty of time to keep tossing them till it's dead. Then, just loot the container, stow the Igniter in a safe pocket, and deliver it back to Tian Wen to complete this one.
