Public events were one of the - if we're honest, relatively few - things that really livened up the open world in the original Destiny. Having listened to the feedback, Bungie have really doubled down on them in the sequel - public events are now more discoverable, more varied, and more important, with Heroic versions that drop greater rewards. They're also integral to the new Flashpoint activities, which drop some of the best rewards in the game.
Where will these events go down? Learn more about Destiny 2's planets and worlds.
To help you master this new system, here's a list of every type of public event in Destiny 2, with instructions for starting their Heroic varieties.
Cabal Excavation (EDZ, Io)
Your job is to capture a Cabal drill. Keep an eye out for a Thresher (the small red fighter ships - Ikora Rey Nova Bombs one in the campaign's first mission); it should first appear between 33 and 40 capture progress, and will reappear at least once more. Destroy it to trigger Heroic mode, which will change the event's objective - rather than capture the drill, now you have to kill a Centurion boss. The hardest part of this one is taking out the Thresher - Coldheart, sniper rifles, fusion rifles, and rocket launchers are recommended. Do that, and it's possible to solo the boss.
Destroy the Arsenal Walker (EDZ, Titan)
The Fallen spider tanks return to Destiny 2. Standard procedure is to shoot its legs until it collapses, exposing the critical spot behind its neck. When you do this, it'll drop a few arc charges. Grab these and plug them into the batteries shielding the bazookas (Scorch Cannons) that are nearby. You need six arc charges in total, and the walker will drop three each time it goes down. Disable all three shields to summon a second Devil Walker, and destroy them both to complete the Heroic version of this event.
Disrupt Vex Construction (Nessus, Io)
This one is all about killing the Vex before they sacrifice themselves to the lantern you're trying to protect. Notice there are three beams of light extending from the lantern: follow them to three plates nearby. Capture each plate to trigger Heroic mode. Stronger Vex will now spawn. Fend them off until the event finishes, still preventing those sacrifices, for the win.
Ether Resupply (EDZ, Nessus)
This event tasks you with taking down a huge Servitor. Simple enough, but it will summon smaller Transport Servitors, which will occasionally shield it. Annoying as that is, the better reason to destroy the Transport Servitors is that's how you trigger Heroic mode. After you kill the first, there will be three in the second wave. You'll have around 30 seconds to kill them all before they leave. Pull it off to trigger Heroic mode. Now just finish the big Servitor for the win.
Glimmer Extraction (EDZ, Nessus)
Three Fallen drill teams must be stopped. What you may not have noticed is each drill site also has a small generator - it'll appear between two of the four nodes that mark each site, and won't spawn until a while after they do. At each site, you have to destroy this generator before killing the last of the four named Fallen targets. Pull it off, and you'll trigger a wave defence fight over a pile of Glimmer - capture the pile while fending off the Fallen, one of which will be a big, pain-in-the-neck Captain. You claim the Heroic win when capture progress is complete.
Injection Rig (EDZ, Nessus)
This is the annoying one that cooks you inside a shield. Your job is to kill three named Psion minibosses, and taking one down will cause the injection rig to vent damaging steam. Rather than evacuate as your HUD advises, you want to shoot the vents that open in the side of the machine. There are three on its top and middle tiers - which can be hard to get to, especially when you're on fire - but only one at the bottom. You have until the end of the third venting phase to destroy all three. When that's done, simply kill the Excavation Valus boss as normal for the Heroic win. Be warned, this one is tough - it's almost impossible if you're solo, in fact.
Taken Blight (EDZ, Io)
Three Blights will spawn in sequence. At each spawning will be one, then two, then three smaller Blights, each of which projects a bubble around itself. The larger Blights are immune, but can be damaged if you pick up the 'Blight receding' buff by stepping inside any of the bubbles around the smaller Blights. It only lasts five seconds, but you can reapply it by stepping inside the bubbles again. Destroy the large Blight to trigger the Heroic version. This summons a Taken boss called a Blightmaker - kill it for the Heroic win.
Witches' ritual (Titan only)
Two shielded Hive Wizards are trying to open a portal, and each has a plate that you'll need to capture to drop their shields. After you kill them, a third boss Wizard will appear after a set time. Kill the third wizard for the regular version, but for the Heroic, you'll need to destroy the shielded crystals at the top of the two columns on either side of the portal. Capture the plates again to drop their shields, and destroy the crystals before the third Wizard appears. Doing so will summon a boss Knight - kill it to complete the Heroic version.