Update 8/25/2016: Added pages on Finding Trade Posts, Sentinels and Wanted Level, in addition to Shielding, Power, and Unstable Plasma Items. Also see my guide to Making Money in No Man's Sky for some tips on the best methods for earning cash, what crafting items are most profitable, and a list of all resources in the game.

Exploring No Man's Sky: Signal Scanners

Finding Crashed Ships, Monoliths, and Upgrades for Gear

Signal Scanners can help you to find Outposts in No Man's Sky, in addition to a number of other interesting things like Monoliths and abandoned ships

No Man's Sky is huge, so your inclination may be to hop from planet to planet perhaps a bit too quickly. Exploring even one planet thoroughly, you can find a lot of upgrades and useful resources. It's likely not every planet has one or more of these things, but you'll sometimes find Signal Scanners, Transmission Towers, Monoliths, and Outposts that all have upgrades for your Multi-tool, ship upgrades, and new modules that can be installed on your ship or suit.

Fly Close to Planets

Exploring planets by flying around them in No Man's Sky

One of the best ways to find things is the most obvious - fly around and look! Just make sure you fly close, so that you can overcome the issues the game's draw distance can cause.

In order to find things like this in NMS - and this applies to everything in this guide - fly close to the planets you visit. The draw distance in-game is kind of bad, so you won't see structures if you're too high up even if they should logically be visible. You'll find far more landmarks if you fly as close at the game will let you. Simply flying around on a planet and observing the scenery, using your scan here and there (just in case), you can visually find many of these things. The first thing listed are signal scanners as they can help you find the other things by providing map markers, but you can find transmission towers and other structures without ever touching a signal scanner!

Signal Scanners

A Signal Scanner in No Man's Sky, with its signature orange beacon that helps it stand out from the other buildings on planets

If you ever see an orange beam of light coming up from the ground while flying around a planet, be sure to land and visit it. These useful structures will help you to locate things on the planets you visit in No Man's Sky. You need an item called a Bypass Chip, crafted for 10 plutonium and 10 iron each, in order to use a signal beacon. You can use multiple bypass chips on one beacon and try many times, the scanner is reusable. When you interact with it you are given four choices that may lead to the following things:

Bypass chips can be used on a signal scanner multiple times, adding more and more destinations to that planet's map.

Transmission - Locates a beacon or transmission tower for you. The former will lead to beacons that send you toward a location with sentient life (very often a trading post). The latter often point you toward the distress signals of crashed ships (that are now abandoned and need repair) once they are used. You may also find observatories which point to alien technology (that you could've found using the monolith option).
Colonial Outpost - Locates a locked outpost, or else a locked manufacturing facility. Use the boltcaster mode on your Multi-tool to break into them. Usually guarded.
Monolith - Locates a monolith, where you can learn alien vocabulary and perhaps increase standing with them. Passing a test will often give you an increased standing with that alien race (decreases if you fail).
Shelter - May locate a drop pod or other type of shelter. You want the former, but are probably more likely to get the small 'houses'. These often contain blueprints. Drop Pods can let you upgrade your Exosuit to have more slots!

Transmission Towers: Find Crashed Ships

Transmission tower puzzle in No Man's Sky

Locating a transmission tower with the signal scanner, you can utilize it to find the last distress signal sent by a crashed ship, now derelict. These often feature a puzzle of sorts, like the one above. Always look for patterns if it's mathematical! In the case of the above puzzle, the numbers begin multiplied by 2, then 3, 4, and 5. The answer would be 120x6 to complete the pattern, thus 720. Answering correctly, you will be given coordinates for the distress signal. This is one of the harder puzzles, some are simply repetitions or numbers that shift position with each number moving to the left one at a time (2567, 5672, 6725, 7256)

Repairing a crashed ship in No Man's Sky

A derelict ship in No Man's Sky. You'll have to repair one or more systems to bring the ship back to full functionality. It was abandoned for being broken, after all.

When you do one right, you'll be able to fly toward the crashed ship. It's usually either a little better, or a little worse in terms of inventory space, but may have desirable upgrades. However, they're usually badly damaged. You'll need to come up with resources to repair each part and may be temporarily stranded if you do not have the materials needed to get the engines online. Hover over each of them and make certain you can repair the ship before you swap, and be sure to move the cargo from your previous ship to the ship you're going to repair. For info on buying ships, which results in much larger leaps in power, see here.

A ship upgrade from a distress beacon in No Man's Sky

A ship upgrade found in the distress beacon of a crashed ship

Sadly, you can't move upgrades from the crashed ship to your own, though there is another means of finding upgrades sometimes. Always look around the crash site for any distress beacons, they may have the schematics to a technology for your ship.

Also Transmission: Observatories and Beacons

Beacons and Observatories can also be found with the Transmission option on the Signal Scanner. Observatories will lead you to places that have scanners that typically locate alien ruins. Beacons will take you to sentient life. Both of these require you to visit first, just like the transmission tower, in order to see the location of the signal they've picked up. Beacons are great as they can lead to small trading posts (indoor type), which will almost always let you buy a new multi-tool from a red box on the wall, or at least an alien who may teach you a new word or tech. See Finding large trading posts using lines from space stations (trade routes). The larger stations do not feature multi-tool upgrades, at least in my experience.

Monoliths

Signal Scanners can lead you toward Monoliths, ancient relics from various alien species in No Man's Sky. They often present you with a question, think carefully, using any knowledge you have of that race's lore, and do not get greedy if it offers you to reach for treasure! These are sacred sites. They'll usually reward you with increased standing with that race and a relic that is worth selling. Be sure to look around the Monolith site for any interactive objects that will teach you new words from that race's language. You can eventually understand what the aliens are saying in NMS.

Colonial Outposts: Ops Centers and Manufacturing Facilities

Buying an upgraded multi-tool with more slots in No Man's Sky

Buying an upgraded Multi-tool with extra slots

Both of these, along with other types of structures can be found using signal scanners. Sometimes you must break the door down with your boltcaster and can expect resistance from sentinels on guard duty. Getting damage upgrades for your boltcaster will let you break the door faster and avoid fighting multiple waves of sentinels. Manufacturing centers often teach you new goods you can make (like precious metals and shielding shards), while Ops Centers teach you new technology if you pass the dialog check.

Other No Man's Sky Guides