Mass Effect 3 planet scanning guide - war assets, artifacts, intel and credits

With the Reapers controlling most of the galaxy, recklessly scanning as you fly around like a child pretending to be an airplane is a great way to get noticed (and murdered) quickly. Knowing exactly where to scan will keep Reaper alertness down, and knowing beforehand what you’ll find is a great way to accumulate credits early on in the game.  

Should the Reapers reach full alertness - and subsequently give chase - leave the system immediately. Reapers are initially slow but pick up speed at an alarming rate and will eventually catch up. Once the Reapers are alert in a system, you’ll have to complete one mission before it’s safe to return. However, knowing where to scan means you can dash in and out, even with the Reapers aware and on your tail.

As you’ll likely realize, not all clusters can be accessed as soon as the game begins. New clusters open up as the story progresses or side missions are completed. Others are not available until a specific quest, such as an N7 assignment, is given to you by Traynor. We’ve outlined exactly when each new cluster was made available to us during our playthrough, though it may vary for you depending on your path.  

Assets in this guide are listed as they appear in the images from left to right. Locations with no planet at the center signify ship wreckages, which grant varying amounts of fuel upon investigation. 

Aethon Cluster

Apien Crest

Arcturus Stream 

Argos Rho

Athena Nebula

Attican Beta

Exodus Cluster

Gemini Sigma

Hades Gamma

Hades Nexus 

Hourglass Nebula

Ismar Frontier

Kite's Nest

Krogan DMZ

Minos Wasteland

Nimbus Cluster

Nubian Expanse

Sigrund's Cradle

Silean Nebula

The Shrike Abyssal

Valhallan Threshold

Be sure to check our other Mass Effect 3 guides and walkthroughs:

Mass Effect 3 walkthrough

Mass Effect 3 romance guide

Mass Effect 3 weapons and armor guide

Join the Discussion
Add a comment (HTML tags are not allowed.)
Characters remaining: 5000
  • Baconator96 - January 7, 2015 6:16 p.m.

    I don't understand, was the mentality behind this guide something along the lines of "I think I'll slap together a bunch of pictures real quick, post them in a borderline unusable format, and misspell every word I type"? Bonus points for not completing the guide.
  • irene-mitzialo - September 28, 2013 7:06 a.m.

    If you use this losers guide , you have to be gay .
  • Flickin-Beanos - December 9, 2013 11:36 a.m.

    If you have to address people as gay or losers, then you clearly have no life.
  • MiKaBoShI - May 25, 2014 4:24 a.m.

    I was already gay before using this guide... what's your point?
  • jeffrey-sickels - October 17, 2014 6:24 p.m.

    I was already gay. What does that have to do with this guide? What a moron.
  • MonkeySeeker - January 26, 2013 10:48 a.m.

    While I haven't listed exactly what is found where, I have posted screenshots of the Leviathan scanning locations, separated into three albums (one for each scanning part of the DLC) if it helps anyone. Leviathan - Find Garneau: Leviathan - Find Ann Bryson: Leviathan - Find Leviathan:
  • max7345 - September 8, 2012 6:26 p.m.

    Looks like they still need to update this with the stuff the Leviathan DLC put in.
  • Darkhawk - March 20, 2012 12:33 p.m.

    Once again, Planet Scanning in ME turned out to be rather silly. In this case, due to the aforementioned flitting in and out of systems once the Reapers are giving chase, I had to mute my TV so I wouldn't hear "REAPERS EVADED" for the fiftieth time in a row. What they should have done (dreaming here) is added an actual spaceflight mini-game in which you dodge through an asteroid belt or something to lose the Reapers.
  • robin-theriault - January 6, 2013 8:49 a.m.

    I agree with the mini-game idead of yours it sounds like it would make looking for resorces much less boring especially when getting away from the reapers
  • VirtualAlex - March 16, 2012 4:35 p.m.

    I like this guide better. Its single-page nature makes it much more usable:
  • slimjim441 - March 6, 2012 4:56 p.m.

    And... bookmarked this page. ^.^
  • KolbitosFruitJuice - March 6, 2012 4:25 p.m.

    This is a very nice article. Very minor spoilers (some of which was already known through achievement list). Could help people make sure they have that perfect ending.