To explore the vastness of space - to boldly go where no one has gone before - is one of the passions of the modern spacefarer. Yet, where do we find the undiscovered reaches of space? What is there to find in this age of faster-than-light transport and established habitable worlds? Do we, as a species, have anywhere left to go? -Arnestus Nguyen, deep space navigator
Those operating in the sphere of Exploration seek to push back the borders of the known galaxy and uncover new sectors and planets. Nobody knows exactly how large the galaxy is, and how many undiscovered planets exist in the Galactic Rim before deep space takes hold. Scientific observations suggest there are many planet-like bodies in the sectors outside of known space, but which of these are habitable or exploitable can only be ascertained by close examination using highly sensitive exploratory probes.
Operations within this sphere are expensive, and the cheaper probes that are available are notoriously prone to malfunction and failure. Therefore this is not a sphere for those on a tight budget. Only a House whose operations elsewhere are highly profitable, or who can secure funding from allies, should consider this as a worthwhile sphere.
The commissioning of exploration missions is a fairly simple process. A new mission can be launched by clicking the link on your Exploration Operations screen. This presents you with a mini-map of the galaxy, which functions in a very similar manner to the standard zoomed out Galactic Chart. Scroll the map to an unexplored sector within range which borders one that is already known to you, and click that sector to select it as the target for the Exploration Mission. Eligible sectors will have a border of orange dashes. Note that the co-ordinates of all sectors in the galaxy are in relation to the position of the Emperor's Homeworld. Thus co-ordinates may change if a new Emperor comes to power. To the right of the mini-map you will see a box for selection of the probe type for your mission. There are four types of exploratory probe available for selection for your mission, of varying quality, reliability and therefore cost. These are as follows:
Note that the more expensive probe classes are only available to those with Exploration as a Secondary (Columbus) or Primary (Magellan) sphere. The overall cost of the mission will also be influenced the distance from your homeworld of the sector to be explored, the attributes of your sphere leader, and the sphere precedence of your exploration sphere. As with all spheres, having exploration as a primary sphere will cut your mission costs by 20%.
The successful mapping of an unexplored sector will take about two game months. Be aware however that exploratory probes will often fail to complete the mapping of their target sector, for a variety of reasons, and your mission may come to a premature and unsuccessful conclusion. Each probe is a highly sensitive piece of equipment, prone to malfunction. The cheaper probes have minimal shielding against radiation and asteroid damage. On top of this, space pirates often operate around and beyond the fringes of known Imperial space, and consider the capture of an exploratory probe a valuable prize for salvage. For these reasons, Explorations are somewhat haphazard and should not be expected to succeed every time - you may have to make several attempts and go to great expense before successfully mapping a sector. Even if the mission is a success, the sector mapped is more than likely to be empty and of little interest. However, by mapping such a sector you will of course open up more distant sectors for exploration.
If you do have the good fortune to discover a hitherto unexplored planet, you will be able to build facilities there immediately. The population of such a planet will normally be virtually non-existent, just a few roving smugglers who prefer to base themselves outside of known space, or lone pioneers and settlers who have travelled into the Galactic Rim and never returned. The economy of such planets will therefore also be undeveloped, often leading to very low prices for any trade goods that may be on offer. Of course, it is possible that you are not the first House to discover the planet, in which case somebody else may already have an established presence there.
Public Knowledge of Unexplored Sectors You may at any time choose to make public the details of a sector you have explored, whether or not it contains a planet. If it does, the planet will become available for development by all Houses, an event that will make the Galactic News and gain your House 5 points of status. You can also reveal the knowledge of your explored sectors just to select Houses, or to fellow alliance members only. Be aware however that even if you choose to guard the location of your newly discovered sectors and planets, any sector that a House successfully explores has a chance of becoming public knowledge. This chance is related both to the number of Houses that know about the sector, and to the population of any planet within that sector. Once people start emigrating to the planet to work in the facilities you build there, the population is sure to rise. The higher the population, the more chance the planet will become public knowledge. It is unlikely you can keep a planet secret for too long - but you will certainly be able to establish a foothold there before anybody else.
Trade routes alone do not increase the chances of a planet becoming public knowledge. It is assumed the traders are employees of your House and therefore under strict orders to keep the knowledge to themselves. Similarly, transport routes, if set up, will not affect the chances although there will be very low demand for regular transport routes to and from sparsely populated newly discovered worlds. You cannot move your Homeworld to a planet that is not public knowledge however, so if you want to do this you must first publicise the appropriate sector.
Note that facilities on a planet that is not public knowledge will not count towards your status total. You will still gain influence on the planet in question, however.
Finally on the subject of Explorations - be aware that an enemy agent in your House may be able to steal knowledge of your explorations. It is a good idea to maintain a counterespionage presence if you wish to avoid this. Also, an attack which results in the ransacking of your House Headquarters can lead to your explorations being stolen by the victorious assailant. Guard your secrets well! Although you will be able to set up an Exploration Concession with another House, if you do wish to share your discoveries and get something in return (via your Embassy).
As seen in the Rulebook
Magellan or Columbus probes are the only ones that are really worth using if they are available to you, the others have a too low chance of success.
Empirical evidence (from Avalon, anyway) indicates that the average planet density in unknown space is drastically lower than in known space (roughly 4% vs. 15%.) ##As of Jan 21: 22 planets in 524 explored squares, 60 planets in the original 20×20 galaxy.
Most galaxies have fully explored all undiscovered planets. each galaxy has 84 planets hardcoded into the map, there are no other planets that can be found.