Quick backstory. Jove Observatories popped up throughout New Eden, followed by Autothysian Lancers. Fast forward a few months; systems that previously had Observatories now have a chance of spawning Drifter Wormholes.

There are 5 types of drifter hole:

V928 J164710 Vidette
R259 J174618 Redoubt
S877 J055520 Sentinel
B735 J110145 Barbican
C414 J200727 Conflux

If you travel through Vale of the Silent, you may see a Drifter wormhole. Warp to it, it will have one of the 5 names above. If you find a Drifter Wormhole in another area with the same WH ID, you have a connection.

Drifter Wormholes spawn with a maximum mass of 375,000,000kg (they're always half-mass). A Muninn is 11,000,000kg and a DNI is 13,500,000kg, so you should exclusively be using Harpy (1,039,500kg), Retribution (1,173,900kg after armor plate) or Torpedo Bomber (1,750,000kg). Basically - you either push a 25-pilot DNI fleet or 150 Assault Frigates on a two-way adventure.

Drifter Wormholes can have 50+ sigs, so don't waste your time parking alts inside and scanning them all down. The fastest approach is to have dedicated nullified interceptor alts to scout the hostile regions, bookmark the inside of the holes and report it here.

There is an ingame channel called 'FRT.DRIFTING' with a list of all the possible drifter locations in Vale, Tribute, and other areas. The channel includes a Dotlan map, recommended clone locations for other regions, and the optimal route if you have multiple scouts.

Hope this helps!

DRIFTER SYSTEMS IN OUR AREA:

Branch

Deklein

Pure Blind

Tribute

Vale of the Silent

DRIFTER SYSTEMS IN OTHER AREAS:
Aridia

Delve

Esoteria

Etherium Reach

Feythabolis

Fountain

Khanid

Malpais

Omist

Querious

Period Basis

Providence

Stain

Tenerifis

The Spire

Thank you to BJK for this information