Editing Known Space (section)

=== Other planets ===
* '''Down''' is the home world of the [[Grogs (Known Space)|Grogs]] and a former Kzinti colony. It orbits "L5-1668",<ref name="RingworldRPG">John Hewitt, et al., ''Larry Niven's Ringworld: Roleplaying Adventure Beneath the Great Arch'', Chaosium Inc., 1984.</ref><ref>The front cover illustration of ''Tales of Known Space: The Universe of Larry Niven'', Del Rey, 1975 (at least 10 printings), has this as "L5-1665".</ref><ref>This is almost certainly a corruption of BD+05 1668 (a.k.a. LHS 33), another name for [[Luyten's Star]].</ref> a faint, cool [[Stellar classification#Class M|M-type]] star, significantly redder and cooler than [[Sun|Sol]] and 12.3 light-years from it. Down is made habitable in part because of its large moon, Sheila. Grogs, though friendly, are feared by humanity, due to their telepathic ability to control the minds of animals (and possibly sentient species as well). Because of this fear, humans have placed a Bussard ramjet field generator in close orbit around Down's sun, thus enabling them to destroy the Grog population should they ever take hostile action against any sentient species.
* '''Jinx''', orbiting [[Sirius]] A, is a massive moon of a gas giant (called ''Primary''), stretched by [[tidal force]]s into an egg shape and [[tidal lock|tidally locked]]. It has habitable areas but has high surface gravity of 1.78 times Earth, near the limits of human extended tolerance. The points nearest to and farthest from Primary (called the "East" and "West" ends) lie elevated out of the atmosphere in vacuum. The atmosphere of the belt-region halfway between them is too dense and too hot to breathe, and is inhabited only by the Bandersnatchi. The zones between the vacuum areas and the high-density belt area have atmosphere breathable by humans. Jinx's "East" and "West" ends become a major ''in vacuo'' manufacturing area. Jinxian humans are short and squat, the strongest bipeds in Known Space. They tend to die early, from heart and circulatory problems. There is a tourist industry which provides substantial useful interplanetary trade credits for the Bandersnatchi, who allow themselves to be hunted by humans under strict protocols.
* '''Wunderland''' is a planet circling [[Alpha Centauri]], and was the earliest extra-solar colony in Known Space's human history. It has a surface gravity of 60% that of Earth's and is hospitable to human life. Wunderland was invaded and its population enslaved by the [[Kzinti]] during the first Man–Kzin War. It was freed near the end of the First War by the human Hyperdrive Armada from We Made It. The system has an asteroid belt in the shape of a crescent, which gives it its name {{Ndash}}the Serpent Swarm. The capital asteroid, Tiamat, houses one of the largest Kzin populations in Known Space.
* '''We Made It''', orbiting [[Procyon]] A, got its name because the first colony ship crash-landed. Gravity is about three-fifths Earth's. The planet's axis is pointed along the plane of its ecliptic (like [[Uranus]]), creating ferocious winds on the order of {{cvt|500|mph|km/h|sigfig=1}}<ref name="RingworldRPG" /><!-- note that this source states that "gullible flatlander tourists may expect gales three times more ferocious" --> during half of the planet's year, forcing the people to live underground. Natives are known as "[[Crashlander]]s", tend to be very tall, and many are [[albino]]s. Their capital, which was the site of their colony ship's landing, is called Crashlanding City. We Made It also has viscous, algae<!-- known as "glurr" -->-choked "oceans" and a big icy moon, ironically named Desert Isle.<ref name="RingworldRPG" />
* '''[[Plateau]]''' in the [[Tau Ceti]] system is [[Venus]]-like, with a plateau (called Mount Lookitthat), half the size of California, rising high enough out of the dense atmosphere to be habitable. Inhabitants ("Mountaineers") are divided into two rigid hereditary castes, the "crew" and the "colonists", depending on whether their ancestors piloted the colonizing vessel. The crew are the upper caste, and hold power through their monopoly on [[organ transplant]]ation and control of the police. The original colonists signed the "Covenant of Planetfall", agreeing that this outcome was just recompense for the labors of the crew during the voyage; that they signed at gunpoint as they were awakened from [[hibernation]] is kept secret from later generations, and also that those who refused, died. This repressive system is overthrown in ''[[A Gift From Earth]]'', and the former inequality and caste system appears to have disappeared by the time ''The Ethics of Madness'' takes place.
* '''Home''' orbits the star [[Epsilon Indi]], about 12 light years from Earth. The planet received its name because of its remarkable similarity to Earth; its day is nearly 24 hours long and its surface gravity is a comfortable 1.08 g. Oceans, mean global temperature, seasons, and moon (Home's moon is called Metaluna, but is often referred to as "the Moon" by Homers) are also similar. According to ''Protector'', the original colonists had planned to call their world "Flatland" as a sort of joke, but once settled on Home they had changed their minds—"a belated attack of patriotism",<ref>Larry Niven, ''Protector'' (Ballantine Books, 1973), 183.</ref> Elroy Truesdale of ''Protector'' muses. The entire population of Home is secretly destroyed as a consequence of Brennan's and Truesdale's war with the [[Pak Protector|Pak]]—Brennan turns the entire population into human Protectors to create an army to fight the Pak invaders. Home is resettled quickly though, since another ramjet with colonists is already on its way when the colony "fails".<ref>Larry Niven, Edward M. Lerner, ''Destroyer of Worlds'' (Tor Books, 2009), 284.</ref> In ''Procrustes'' and other later stories, Home is once again presented as a vibrant colony.
* '''Canyon''' was once an uninhabitable [[Mars]]-like world known as Warhead. It is the second of seven planets around [[p Eridani|p&nbsp;Eridani&nbsp;A]], 22&nbsp;light-years from Earth.<ref name="RingworldRPG" /> It was used as a military outpost by the Kzinti, until the planet was hit by a weapon called the "Wunderland Treatymaker" during the Third War. The attack tore a long, narrow, kilometers-deep [[Impact crater|crater]] into the crust approximately the size of the [[Baja Peninsula]]. The air and moisture in the thin atmosphere gathered at the bottom of this artificial canyon, creating a breathable environment, complete with a sea at the bottom. The planet was then renamed for the crater, and settled by humans in a huge city running up the crater wall. Archaic (hyper-aggressive and intractable) Kzinti were entombed in stasis field shells during the attack and are still beneath the lava, and someday, somebody will have to deal with them. The attack by the Wunderland Treatymaker is detailed as a part of ''Destiny's Forge'' by Paul Chafe, a part of the Man–Kzin Wars shared universe.
* '''Gummidgy''' is a [[jungle]] world popular with hunters. It is home to the Gummidgy Orchid-Thing, a [[sessility (zoology)|sessile]] carnivore which hangs from trees and is a popular trophy for the wealthy. It orbits [[CY Aquarii]],<ref>Oddly, the ''Ringworld Roleplaying'' book places it around [[Fomalhaut]] instead, in contradiction with primary sources such as Niven's ''Grendel'' short story.</ref> a [[blue giant]] [[SX Phoenicis]] variable star; due to the resulting high levels of [[ultraviolet]] light, most humans (except Jinxians) require [[melanin]]-boosting medication to venture outdoors.
* '''Fafnir''' is a former Kzin colony covered almost entirely in water. When under Kzinti control it was called Shasht, a Kzin word meaning "burrowing murder". It was captured by humans during the Man–Kzin Wars. Humans and Kzinti now cohabitate. The humans prefer to live on the coral islands while the Kzinti prefer the single large continent which they continue to call Shasht.
* '''[[Margrave]]''' is a late addition to the family of Human colonies. In the ''Ringworld'' era it is still a frontier world, and is home to enormous birds the inhabitants have dubbed "[[roc (mythology)|roc]]s". It orbits [[Lambda Serpentis]] (27 Serpentis), a G0 star 34.7 light-years from Earth.<ref name="RingworldRPG" /> It is named after its discoverer, J. Margrave Julland.
* '''Silvereyes''' is, at the time of ''Ringworld'', the furthest Human world from Earth (21.3 light-years, 60 days at Quantum-I hyperdrive speeds), orbiting [[Beta Hydri]]. In Niven's obscure story ''The Color of Sunfire''<ref name="sunfire">[http://www.larryniven.net/stories/color_of_sunfire.shtml "The Color of Sunfire"] {{Webarchive|url=https://web.archive.org/web/20130206100704/http://larryniven.net/stories/color_of_sunfire.shtml |date=2013-02-06 }}. ''Known Space: The Future Worlds of Larry Niven''. Larry Niven (larryniven.net). Retrieved 2014-08-16.</ref> it has entire continents covered with Slaver sunflowers (bred as defense for Thrint manors, they focus sunlight using silver leaves as [[parabolic reflector]]s), giving it an appearance from orbit of having "silver eyes". The ''Man–Kzin Wars'' books, conversely, have it entirely covered by a world ocean, with groves of sunflowers growing up from the bottom of the ocean. The ''Ringworld Roleplaying Game'' describes it as an ocean planet dotted with island shield volcanoes.<ref name="RingworldRPG" />
* '''Hearth''' is the homeworld of the Pierson's Puppeteers. With a population of around one trillion, it is covered by [[Arcology|arcologies]], most over one mile tall. Its industries and population generate so much waste heat it no longer requires a star for warmth (the four other "farmworlds", simply named "Nature Preserves" or NP1, NP2, etc., use artificial orbital lights to grow food). Together these five planets (with a sixth added later, as detailed in ''[[Fleet of Worlds]]'') are often referred as the Fleet of Worlds and do not orbit any star, but use Outsider-manufactured drives to move in order to flee the [[Galactic Center|galactic core]] explosion discovered by Beowulf Schaeffer. They orbit about each other in a [[Klemperer rosette]].
* '''Kobold''' was a tiny artificial world created in the outer Sol system by [[Protector (novel)|Jack Brennan]], a human Protector, composed of a small sphere of [[neutronium]] in the center ringed by a larger [[torus]]. Gravity generators facilitated movement between the two sections and were used in games and art. Brennan destroyed Kobold just prior to leaving for his war with the Pak Protectors.
* The '''[[Ringworld]]''' is an artificial world structure with three million times the surface area of Earth, built in the shape of a giant ring circling its sun, a million miles wide and with a diameter of 186 million miles. It was built by the Pak, who either abandoned it, or more likely died out much as the Earth Pak did, due to a lack of the Tree-of-Life, a yamlike root which produces the conversion to Protector-stage Pak (which required a very specifically targeted soil chemistry to grow). It is inhabited by a number of different evolved hominid species, and includes representative samples of Bandersnatchi, Martians and Kzinti, and possibly other alien races that existed at the time of its construction.
* '''Sheathclaws''' is a planet colonized by humans aboard ''Angel's Pencil'' and descendants of a rogue Kzin telepath. It orbits an as-yet-unspecified star 98 light-years from Earth, and kept its existence secret for several centuries. The Patriarchy would dearly love to capture the entire population of potential Telepaths and press them into service.
* '''[[Kzin#Homeworld|Kzin]]''' (so called by Humans) is the homeworld of the Kzinti. Its name in the Hero's Tongue translates as "Home-of-the-Kzinti" or "Kzinhome". It orbits [[61 Ursae Majoris]] and has higher gravity than Earth and more oxygen in the atmosphere. It has two moons, known as the Hunter's Moon and the Traveler's Moon.
* '''Cue Ball''' is an uninhabitable ice world orbiting [[Beta Lyrae]].
* '''Jm'ho''' is a moon similar to Europa, homeworld to the Gw'oth. It orbits a gas giant called Tl'ho. The star is simply called G567-X2 in the Puppeteers' catalogue
* '''Kl'mo''' is a Gw'oth colony founded by Ol't'ro. Not much is explained about this world, except that it seems very primitive and has a very strong gravity.
* '''Oceanus''' is a primitive world briefly surveyed by the crew of ''Explorer'' in ''[[Fleet of Worlds]]''.