The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, the dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury. The Solar System formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter.
Introduction
Solar System
Solar System | Introduction
Mercury. Mercury Mercury Pluto.
where is sedna located in the solar system
user
In the outer reaches of the Solar System.
assistant
who discovered it?
user
Michael Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University).
assistant
who gave it it's name?
user
Michael Brown.
assistant
what does it look like?
user
It is a large planetoid, surface is redd.
assistant
the system mentioned above, what does it consist of?
user
Sun, the giant planets, four terrestrial planets, the dwarf planets, moons, asteroids, and comets.
assistant
the first thing mentioned, does it have any religious inclusion?
user
Yes, the Sun was worshipped as the god Ra, personified as the goddess.
assistant
which religion did they worship him as the above?
user
Proto-Indo-European religion,  ancient Greek religion, ancient Sumerians.
assistant
does the ancient religion have any concepts of after death revival?
user
They believed in an underworld where the spirits of the dead went after death ,also embraced the idea of reincarnation.
assistant
what is the smallest planet in the system mentioned earlier?
user
51 Eridani b is a young Jupiter-like planet and was photographed, in near-infrared light, on December 21, 2014. The study, led by Bruce Macintosh, a professor of physics at Stanford University and confirmed by Christian Marois found that methane and water were abundant in the atmosphere of the planet and its mass was only slightly larger than Jupiter's. It is the smallest exoplanet directly imaged to date.
51 Eridani | Planetary system
With a minimum mass of around 4.5 Earths, it is a small Super-Earth.
Gliese 676 | Planetary system
The smallest asteroids discovered (based on absolute magnitude "H") are with and with both with an estimated size of about 1 meter. In 2006, the term "small Solar System body" was also introduced to cover both most minor planets and comets. Other languages prefer "planetoid" (Greek for "planet-like"), and this term is occasionally used in English especially for larger minor planets such as the dwarf planets as well as an alternative for asteroids since they are not star-like. The word "planetesimal" has a similar meaning, but refers specifically to the small building blocks of the planets that existed when the Solar System was forming.
Asteroid | Terminology
This is a list of the lists of small Solar System bodies and dwarf planets.
Lists of small Solar System bodies | Introduction
A small Solar System body (SSSB) is an object in the Solar System that is neither a planet, a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies' ". This encompasses all comets and all minor planets other than those that are dwarf planets. Thus SSSBs are: the comets; the classical asteroids, with the exception of the dwarf planet Ceres; the trojans; and the centaurs and trans-Neptunian objects, with the exception of the dwarf planets Pluto, Haumea, Makemake, and Eris and others that may turn out to be dwarf planets.
Small Solar System body | Introduction
The sizes are listed in units of Earth radii (). All planets listed are smaller than Earth and being up to 0.7 Earth radii.
List of smallest exoplanets | List
After its return to Earth in 2010, the mineralogy, petrography, chemistry, and isotope ratios of these particles have been studied in detail, providing insights into the evolution of the Solar System. "Itokawa" is the smallest asteroid ever photographed and visited by a spacecraft.
25143 Itokawa | Introduction
The planets formed by accretion from this disc, in which dust and gas gravitationally attracted each other, coalescing to form ever larger bodies. Hundreds of protoplanets may have existed in the early Solar System, but they either merged or were destroyed, leaving the planets, dwarf planets, and leftover minor bodies. Due to their higher boiling points, only metals and silicates could exist in solid form in the warm inner Solar System close to the Sun, and these would eventually form the rocky planets of Mercury, Venus, Earth, and Mars. Because metallic elements only comprised a very small fraction of the solar nebula, the terrestrial planets could not grow very large.
Solar System | Formation and evolution
The term was coined in Asimov's essay "What's in a Name?", which first appeared in The "Los Angeles Times" in the late 1980s and was reprinted in his 1990 book "Frontiers"; the term was later revisited in his essay, "The Incredible Shrinking Planet" which appeared first in "The Magazine of Fantasy and Science Fiction" and then in the anthology "The Relativity of Wrong" (1988). Asimov noted that the Solar System has many planetary bodies (as opposed to the Sun and natural satellites) and stated that lines dividing "major planets" from minor planets were necessarily arbitrary. Asimov then pointed out that there was a large gap in size between Mercury, the smallest planetary body that was considered to be undoubtedly a major planet, and Ceres, the largest planetary body that was considered to be undoubtedly a minor planet.
Mesoplanet | History
Ceres () is the smallest identified dwarf planet in the solar system, but is significantly the largest object in the asteroid belt. It was discovered on 1 January 1801 by Giuseppe Piazzi, and is named after Ceres, the Roman goddess of growing plants, the harvest, and of motherly love. It was the first asteroid discovered, taking up about one-third of the entire mass of its asteroid belt. The classification of Ceres has changed more than once and has been the subject of some disagreement. Johann Elert Bode believed Ceres to be the "missing planet" he had proposed to exist between Mars and Jupiter, at a distance of 419 million km (2.8 AU) from the Sun.
Planets in astrology | Ceres
Some of the larger small Solar System bodies may be reclassified in future as dwarf planets, pending further examination to determine whether or not they are in hydrostatic equilibrium.
Small Solar System body | Definition
There are eight planets in the Solar System, which are in increasing distance from the Sun: Jupiter is the largest, at 318 Earth masses, whereas Mercury is the smallest, at 0.055 Earth masses. The planets of the Solar System can be divided into categories based on their composition:
Planet | Solar System
The Beta Caeli system is similar to our real-life solar system, with a barren, rocky inner planet, terrestrial planets in the habitable zone of the inner system, followed by gas giants in the outer system that first increase and then decrease in size, and a tiny rock outermost. The naming of the Caelian planets closely matches that of naming planets in our solar system. But while our system uses the names of Roman deities (except for Uranus), Caeli has Greek ones; Gaea is the Greek goddess of the Earth, and Rhea is her daughter. In addition, as Beta Caeli is brighter and hotter than the Sun, the Caelian planets are more distant from their sun than their Solar System analogs are.
Alien Legacy | Planetary systems
The Solar System also contains smaller objects. The asteroid belt, which lies between the orbits of Mars and Jupiter, mostly contains objects composed, like the terrestrial planets, of rock and metal. Beyond Neptune's orbit lie the Kuiper belt and scattered disc, which are populations of trans-Neptunian objects composed mostly of ices, and beyond them a newly discovered population of sednoids. Within these populations, some objects are large enough to have rounded under their own gravity, though there is considerable debate as to how many there will prove to be. Such objects are categorized as dwarf planets. The only certain dwarf planet is Pluto, with another trans-Neptunian object, Eris, expected to be, and the asteroid Ceres at least close to being a dwarf planet.
Solar System | Introduction
It has been a disappointment all along, for it did not turn out to be what one could reasonably have expected". In 1978, Pluto's moon Charon was discovered. By measuring Charon's orbital period, astronomers could accurately calculate Pluto's mass for the first time, which they found to be much smaller than expected. Pluto's mass was roughly one twenty-fifth of Mercury's, making it by far the smallest planet, smaller even than the Earth's Moon, although it was still over ten times as massive as the largest asteroid, Ceres.
IAU definition of planet | Background
Cha 110913-773444 is the smallest brown dwarf found to date (), and if it formed a planetary system, it would be the smallest known object to have one.
Brown dwarf | Formation and evolution
Later literature began to accept that there were limits set by temperature, gravity, atmospheric pressure and composition, or the presence of liquids that would set bounds on the possibility of life as we know it existing on other planets. By the 19th century the Moon was given up as an airless desert, incapable of supporting life on its surface (hopes for subsurface life continued until later). Jupiter and the planets beyond were too large, too cold, and had atmospheres composed of poisonous chemicals. Mercury was too close to the Sun and its surface was exposed to extremes of temperature. The asteroids were too tiny and airless.
Solar System in fiction | Introduction
It is not presently clear whether a lower size bound will be established as part of the definition of small Solar System bodies in the future, or if it will encompass all material down to the level of meteoroids, the smallest macroscopic bodies in orbit around the Sun. (On a microscopic level there are even smaller objects such as interplanetary dust, particles of solar wind and free particles of hydrogen.) Except for the largest, which are in hydrostatic equilibrium, natural satellites (moons) differ from small Solar System bodies not in size, but in their orbits. The orbits of natural satellites are not centered on the Sun, but around other Solar System objects such as planets, dwarf planets, and small Solar System bodies.
Small Solar System body | Definition
Its mass is roughly half that of the planet Mercury. The smallest known planet orbiting a main-sequence star other than the Sun is Kepler-37b, with a mass (and radius) slightly higher than that of the Moon.
Planet | Mass
OGLE-2005-BLG-390L has one known planet, which was discovered using the technique of gravitational microlensing. Indications are that the planet is about five times Earth mass, orbiting at about 2.6 astronomical units from the parent star. The discovery was announced on January 25, 2006. OGLE-2005-BLG-390Lb was once considered one of the smallest known extrasolar planets around a main sequence star, possibly rocky, with a mass around 5.5 times that of the Earth. The orbital radius (assuming a circular orbit) of the planet is 2.6 AU, however the orbital elements are unknown. Based on its low mass and estimated temperature of around 50 K, the planet is thought to consist mainly of ices, like Pluto or Uranus, rather than being a Jupiter-like gas giant.
OGLE-2005-BLG-390L | Planetary system
This minor planet was named from Egyptian mythology after Aten, the ancient Egyptian god of the solar disk, originally an aspect of the god Ra. The official was published by the Minor Planet Center on 1 August 1978 ().
2062 Aten | Naming
In addition to these two regions, various other small-body populations, including comets, centaurs and interplanetary dust clouds, freely travel between regions. Six of the planets, the six largest possible dwarf planets, and many of the smaller bodies are orbited by natural satellites, usually termed "moons" after the Moon. Each of the outer planets is encircled by planetary rings of dust and other small objects.
Solar System | Introduction
It was once expected that any icy body larger than approximately 200 km in radius was likely to be in hydrostatic equilibrium (HE). However, (r = 470 km) is the smallest body for which detailed measurements are consistent with hydrostatic equilibrium, whereas Iapetus (r = 735 km) is the largest icy body that has been found to not be in hydrostatic equilibrium. For simplicity and comparative purposes, the values are manually calculated assuming a sphericity of 1. The size of solid bodies does not include an object's atmosphere. For example, Titan looks bigger than Ganymede, but its solid body is smaller.
List of Solar System objects by size | Larger than 400 km
Asteroids, comets, and meteoroids are all debris remaining from the nebula in which the Solar System formed 4.6 billion years ago.
Geology of solar terrestrial planets | Small Solar System bodies
The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being primarily composed of rock and metal. The four outer planets are giant planets, being substantially more massive than the terrestrials. The two largest planets, Jupiter and Saturn, are gas giants, being composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are ice giants, being composed mostly of substances with relatively high melting points compared with hydrogen and helium, called volatiles, such as water, ammonia and methane. All eight planets have almost circular orbits that lie within a nearly flat disc called the ecliptic.
Solar System | Introduction
Small Gods is the thirteenth of Terry Pratchett's "Discworld" novels, published in 1992. It tells the origin of the god Om, and his relations with his prophet, the reformer Brutha. In the process, it satirises religious institutions, people, and practices, and the role of religion in political life.
Small Gods | Introduction
The upper mass limit for planethood is roughly 13 times Jupiter's mass for objects with solar-type isotopic abundance, beyond which it achieves conditions suitable for nuclear fusion. Other than the Sun, no objects of such mass exist in the Solar System; but there are exoplanets of this size. The 13-Jupiter-mass limit is not universally agreed upon and the Extrasolar Planets Encyclopaedia includes objects up to 60 Jupiter masses, and the Exoplanet Data Explorer up to 24 Jupiter masses. The smallest known planet is PSR B1257+12A, one of the first extrasolar planets discovered, which was found in 1992 in orbit around a pulsar.
Planet | Mass
Monoceros contains two super-Earth exoplanets in one planetary system: COROT-7b was detected by the COROT satellite and COROT-7c was detected by HARPS from ground-based telescopes. Until the announcement of Kepler-10b in January 2011, COROT-7b was the smallest exoplanet to have its diameter measured, at 1.58 times that of the Earth (which would give it a volume 3.95 times Earth's). Both planets in this system were discovered in 2009.
Monoceros | Planets
The following is a list of TNOs with the largest aphelion in descending order.
List of Solar System objects by greatest aphelion | Minor planets
The planets in the system have a size between Neptune and Saturn. Only planet b has a size similar to Jupiter. Models predict that the planets have a minimum core mass of 5 and are surrounded by a thick envelope that make up 20% of their mass. The total mass of planet c and d was predicted to be 2 - 28 and the total mass of planet d and b was predicted to be 9 - 120 . In a follow-up paper the mass of V1298 Tauri b was constrained to <2.2 .
V1298 Tauri | Planetary System
Irregularities in the disk also suggest the presence of at least one planet, about the size of Jupiter, in an orbit large enough to allow the formation of smaller rocky planets closer to the star. Regardless of its ultimate tally of planetary companions, the fact that it has an estimated age of just 455 million years suggests that the Vega system is too young to have fostered the development of life or a complex biosphere on any of its worlds. The name Wega (later Vega) comes from a loose transliteration of the Arabic word ' meaning "falling" or "landing," via the phrase ', "the falling eagle." The star figures prominently in the mythology of cultures as diverse as the Polynesian, ancient Greek, Roman, Chinese (see "Qi Xi"), Persian, and Hindu.
Vega in fiction | Introduction
The inner Solar System, the region of the Solar System inside 4 AU, was too warm for volatile molecules like water and methane to condense, so the planetesimals that formed there could only form from compounds with high melting points, such as metals (like iron, nickel, and aluminium) and rocky silicates. These rocky bodies would become the terrestrial planets (Mercury, Venus, Earth, and Mars). These compounds are quite rare in the Universe, comprising only 0.6% of the mass of the nebula, so the terrestrial planets could not grow very large. The terrestrial embryos grew to about 0.05 Earth masses () and ceased accumulating matter about 100,000 years after the formation of the Sun; subsequent collisions and mergers between these planet-sized bodies allowed terrestrial planets to grow to their present sizes (see Terrestrial planets below).
Formation and evolution of the Solar System | Formation of the planets
Ceres became "(1) Ceres", Pallas became "(2) Pallas", and so on. By the 1860s, the number of known asteroids had increased to over a hundred, and observatories in Europe and the United States began referring to them collectively as "minor planets", or "small planets", though it took the first four asteroids longer to be grouped as such. To this day, "minor planet" remains the official designation for all small bodies in orbit around the Sun, and each new discovery is numbered accordingly in the IAU's Minor Planet Catalogue.
Definition of planet | Minor planets
Phaëton is a name given to a supposed planet existing in the past between the orbits of Mars and Jupiter, which no longer exists, having become the Solar System's asteroid belt. Proposed not long after the discovery of multiple asteroids at the beginning of the 19th century, the idea that the asteroids were fragments of a single planet was gradually abandoned over the course of the middle decades of the 20th century in favor of the conclusion that no planet had ever accreted in the region of the asteroid belt in the first place. In fiction, various other names were given to the same or similar concepts.
Fictional planets of the Solar System | Phaëton
Compared to many other planetary systems, the Solar System stands out in lacking planets interior to the orbit of Mercury. The known Solar System also lacks super-Earths (Planet Nine could be a super-Earth beyond the known Solar System). Uncommonly, it has only small rocky planets and large gas giants; elsewhere planets of intermediate size are typical—both rocky and gas—so there is no "gap" as seen between the size of Earth and of Neptune (with a radius 3.8 times as large). Also, these super-Earths have closer orbits than Mercury. This led to the hypothesis that all planetary systems start with many close-in planets, and that typically a sequence of their collisions causes consolidation of mass into few larger planets, but in case of the Solar System the collisions caused their destruction and ejection.
Solar System | Comparison with extrasolar systems
Here he was offered six biological robot women with which to have sex, saw the Elohim create his clone, and taught the techniques of sensual meditation. The scholar of religion James R. Lewis noted that Raël's account of encountering the Elohim was similar to those of the "classic UFO contactees" of the 1950s and 1960s. The Elohim are described as being physically smaller than humans, with pale green skin and almond-shaped eyes, and divide into seven different races, although Raëlians are forbidden from painting or sketching them. Their planet, Raël stated, is outside our solar system but within our own Milky Way galaxy.
Raëlism | The Elohim
The small planet radius gap (also called the Fulton gap, photoevaporation valley, or Sub-Neptune Desert) is an observed scarcity of planets with radii between 1.5 and 2 times Earth's radius, likely due to photoevaporation-driven mass loss. A bimodality in the Kepler exoplanet population was first observed in 2013, and was noted as possibly confirming an emerging hypothesis that photoevaporation could drive atmospheric mass loss on close-in, low-mass planets. This would lead to a population of bare, rocky cores with smaller radii at small separations from their parent stars, and planets with thick hydrogen- and helium-dominated envelopes with larger radii at larger separations.
Small planet radius gap | Introduction
The paper was never formally accepted, and has been withdrawn until the detection is confirmed. Scientists' reactions to the notice were largely sceptical; Mike Brown commented that, "If it is true that ALMA accidentally discovered a massive outer Solar System object in its tiny, tiny, tiny, field of view, that would suggest that there are something like 200,000 Earth-sized planets in the outer Solar System ... Even better, I just realized that this many Earth-sized planets existing would destabilize the entire Solar System and we would all die."
Planets beyond Neptune | Other proposed planets
Being reduced from a small star to a life planet is not possible, as well as being reduced from a small planet to an asteroid. In these cases, the player is respawned, with random mass, close to the place where they collided.
Solar 2 | Gameplay
At the time of discovery of the planet HD 49674 b in 2002, it was the least massive planet known, very close to the boundary between sub-Jupiter mass and Neptune-mass at 0.1 M. This planet orbits very close to the star.
HD 49674 | Planetary system
Centaurs with measured diameters listed as possible dwarf planets according to Mike Brown's website include 10199 Chariklo, , 2060 Chiron, and 54598 Bienor.
Centaur (small Solar System body) | Possible dwarf planet raise further issues
Below is a list of the smallest exoplanets so far discovered, in terms of physical size, ordered by radius. Some of these are unconfirmed and/or controversial.
List of smallest exoplanets | Introduction
Further developments are expected with more physical data on Kuiper belt objects.
Centaur (small Solar System body) | Hypotheses of origin
Makemake (45.79 AU average), although smaller than Pluto, is the largest known object in the "classical" Kuiper belt (that is, a Kuiper belt object not in a confirmed resonance with Neptune). Makemake is the brightest object in the Kuiper belt after Pluto. It was assigned a naming committee under the expectation that it would prove to be a dwarf planet in 2008. Its orbit is far more inclined than Pluto's, at 29°. Haumea (43.13 AU average) is in an orbit similar to Makemake, except that it is in a temporary 7:12 orbital resonance with Neptune. It was named under the same expectation that it would prove to be a dwarf planet, though subsequent observations have indicated that it may not be a dwarf planet after all.
Solar System | Makemake and Haumea
In 2002, a possible planet was discovered transiting the star, and after additional observations to rule out false positives, it was confirmed. At the time of discovery it was the shortest period planet.
OGLE-TR-56 | Planetary system
It was roughly one-twentieth the mass of Mercury, which made Pluto by far the smallest planet. Although it was still more than ten times as massive as the largest object in the asteroid belt, Ceres, it had only one-fifth the mass of Earth's Moon. Furthermore, having some unusual characteristics, such as large orbital eccentricity and a high orbital inclination, it became evident that it was a different kind of body from any of the other planets. In the 1990s, astronomers began to find objects in the same region of space as Pluto (now known as the Kuiper belt), and some even farther away.
Dwarf planet | History of the concept
K2-148b is a confirmed super-Earth, probably rocky, closely orbiting a small orange dwarf star. It is the innermost of three Super-Earths around the star K2-148, which is in a wide binary pair with the M0.5V red dwarf EPIC 220194953. K2-148b is the smallest planet of the system, at about a third larger than Earth, and could be terrestrial in nature. However, the three planets do not exhibit significant transit timing variations, implying that they could have relatively low masses. The planet was validated in early 2018 by Hirano "et al." and is too hot for known life.
K2-148b | Introduction
In 2008, it was considered to be a dwarf planet based on its lightcurve amplitude and the assumption that it was larger than in diameter. Because is a member of the Haumea family, it is assumed to have an albedo of around 0.7, which would result in a diameter of about .
(55636) 2002 TX300 | Size
This minor planet was named for the Egyptian creator deity Ptah. In Egyptian mythology, he is the creator of the universe and god of craftsmen and architects. The deity was generally represented in a human form with a sceptre and an ankh. The approved naming citation was published by the Minor Planet Center on 16 May 1992 ().
5011 Ptah | Naming
In 2012, Johnson's team discovered three small rocky exoplanets in a red dwarf star system observed with the Kepler space telescope. The system was renamed Kepler-42 and the outermost planet was found to be nearly as small as Mars, making it the smallest known exoplanet at the time. A subsequent study used the host star's similarity to Barnard's Star and observations from the Keck Observatory to more precisely measure the properties of the system, including the sizes of the three planets.
John Johnson (astronomer) | Research
The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, the dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury. The Solar System formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter.
Solar System | Introduction
This planet was the first known instance of a fourth extrasolar planet in one system, and was the shortest-period planet until the discovery of PSR J1719-1438 b. The measurements that led to the discovery of this planet also confirmed the existence of 55 Cancri c.
55 Cancri | Planetary system
The discovery of a planet, MOA-2007-BLG-192Lb, orbiting this object was announced on June 2, 2008. This planet, with a mass of approximately 3.3 times that of Earth, is one of the smallest known extrasolar planets. It was found when it caused a gravitational microlensing event on the night of May 24, 2007, which was detected as part of the MOA-II gravitational microlensing survey at the Mount John University Observatory in New Zealand.
MOA-2007-BLG-192L | Planetary system
The minor planet and centaur 10199 Chariklo, with a diameter of about , is the smallest celestial object with confirmed rings and the fifth ringed celestial object discovered in the Solar System, after the gas giants and ice giants. Orbiting Chariklo is a bright ring system consisting of two narrow and dense bands, 6–7 km (4 mi) and 2–4 km (2 mi) wide, separated by a gap of . The rings orbit at distances of about from the centre of Chariklo, a thousandth the distance between Earth and the Moon. The discovery was made by a team of astronomers using ten telescopes at various locations in Argentina, Brazil, and Chile in South America during observation of a stellar occultation on 3 June 2013, and was announced on 26 March 2014.
Rings of Chariklo | Introduction
In late 2009, Qian estimated a minimum mass of 10.7 Jupiter masses and orbital period of 7.56 years for this planet, probably located at 3.29 Astronomical Units. This has since been disproven by further measurements of the eclipse times of the binary stars.
NN Serpentis | Planetary system
However, Brutha is also considered unintelligent, since he never learned to read, and rarely thinks for himself. This begins to change after Brutha discovers Ephebe's philosophers; the idea of people entertaining ideas they're not certain they believe or even understand, let alone starting fistfights over them, is an entirely new concept to him.
Small Gods | Plot
K2-3c also known as EPIC 201367065 c is an exoplanet orbiting K2-3 a red dwarf every 24 days. It is 144 ly away. It has a density of 1.82g/cm, indicating that it could be a Gas dwarf or a mini-Neptune. It is one of the smallest gas planets ever discovered. Despite not being the smallest planet in the system by radius, by mass it is by far the least massive, with a mass only double that of Earth.
K2-3c | Introduction
Of these, Draugr is the smallest exoplanet ever detected, at a mass of twice that of the Moon. Another system is PSR B1620−26, where a circumbinary planet orbits a neutron star-white dwarf binary system. Also, there are several unconfirmed candidates. Pulsar planets receive little visible light, but massive amounts of ionizing radiation and high-energy stellar wind, which makes them rather hostile environments.
Neutron star | Planets
A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and – acconding to the International Astronomical Union but not all planetary scientists – has cleared its neighbouring region of planetesimals. The term "planet" is ancient, with ties to history, astrology, science, mythology, and religion. Apart from Earth itself, five planets in the Solar System are often visible to the naked eye. These were regarded by many early cultures as divine, or as emissaries of deities. As scientific knowledge advanced, human perception of the planets changed, incorporating a number of disparate objects.
Planet | Introduction
The main planets hosting intelligent life and their stars are Earth and Mars (Sol), Osiris, Isis and Thoth (Procyon), Krishna and Vishnu (Tau Ceti), Ormazd (Lalande 21185), and Kukulkan (Epsilon Eridani). These are the Terran designations; the local ones are rarely revealed. All are named for Terran gods because de Camp assumes that Terrans will have carried their penchant for naming planets after deities to other star systems, with each planetary system being named for a different pantheon – Egyptian for Procyon, Hindu for Tau Ceti, Persian for Lalande 21185, and Mesoamerican for Epsilon Eridani. (There is some confusion regarding the last of these; in addition to Kukulkan, another planet, Thor, is also stated to be a planet of Epsilon Eridani, though Thor belongs to a different pantheon from Kukulkan.) Some other planets are also occasionally mentioned in the series, and their inhabitants sometimes seen.
Viagens Interplanetarias | Star systems and planets
In 2018, a planet was discovered orbiting 40 Eridani A with a minimum mass of Earth masses. The planet has an orbit of 42 days, and lies considerably interior to the habitable zone, receiving 9 times more stellar flux than Earth, which is an even greater stellar flux amount than Mercury, the innermost planet in our solar system, on average receives from our Sun. It is one of the closest Super-Earths known, the closest discovered to date () within a multiple star system.
40 Eridani | Planetary system
The International Astronomical Union (IAU) defined in August 2006 that, in the Solar System, a planet is a celestial body which: Among other things, this definition caused Pluto to no longer be classified as a planet, a change from how it had been widely considered until that point. A non-satellite body fulfilling only the first two of these criteria (such as Pluto) is classified as a "dwarf planet". According to the IAU, "planets and dwarf planets are two distinct classes of objects". In other words, "dwarf planets" are not planets. A non-satellite body fulfilling only the first criterion is termed a "small Solar System body" (SSSB).
IAU definition of planet | Introduction
'little person').
HD 102117 | Planetary system
V1298 Tauri has four confirmed planets of which planets c, d and b are near a 1:2:3 resonance (with periods of 8.25, 12.40 and 24.14 days). Planet e only shows a single transit in the K2 light curve and has a period larger than 36 days. Planet e might be in a low-order resonance (of 2:3, 3:5, 1:2, or 1:3) with planet b. The system is very young and might be a precursor of a compact multiplanet system. The 2:3 resonance suggests that some close-in planets may either form in resonances or evolve into them on timescales of less than 10 Myr.
V1298 Tauri | Planetary System
At the end of the "Death of the New Gods" mini-series, with all the gods now dead, the combined entity born from the melding of the Source and the Anti-Life Equation merges Apokolips and New Genesis into a single new planet with characteristics in common with both the former worlds.
Apokolips | "Death of the New Gods"
Nature: Technology: Self:
Tiny Planets | Episodes
This implies that small, including Earth-size, planets may have readily formed at earlier epochs in the Universe's history when metals were more scarce. We report Kepler spacecraft observations of Kepler-444, a metal-poor Sun-like star from the old population of the Galactic thick disk and the host to a compact system of five transiting planets with sizes between those of Mercury and Venus. We validate this system as a true five-planet system orbiting the target star and provide a detailed characterization of its planetary and orbital parameters based on an analysis of the transit photometry. Kepler-444 is the densest star with detected solar-like oscillations.
Kepler-444 | Characteristics
On June 13 2002, a 2.1 M planet HD 73526 b was announced orbiting HD 73526 in an orbit just a little smaller than that of Venus' orbit around the Sun. This planet receives insolation 3.65 times that of Earth or 1.89 times that of Venus. This was a single planet system until 2006 when a 2.3 M second planet HD 73526 c was discovered. This planet forms a 2:1 orbital resonance with planet b. Although these are minimum masses as the inclinations of these planets are unknown, orbital stability analysis indicated that orbital inclinations of both planets are likely to be near 90°, making the minimum masses very close to the true masses of the planets.
HD 73526 | Planetary system
Mercury is the smallest and innermost planet in the Solar System. Its orbit around the Sun takes 87.97 days, the shortest of all the planets in the Solar System. It is named after the Greek god Hermes (Ερμής), translated into Latin Mercurius Mercury, god of commerce, messenger of the gods, mediator between gods and mortals. Like Venus, Mercury orbits the Sun within Earth's orbit as an inferior planet, and its apparent distance from the Sun as viewed from Earth never exceeds 28°. This proximity to the Sun means the planet can only be seen near the western horizon after sunset or eastern horizon before sunrise, usually in twilight.
Mercury (planet) | Introduction
Starting in 1801, astronomers discovered Ceres and other bodies between Mars and Jupiter that for decades were considered to be planets. Between then and around 1851, when the number of planets had reached 23, astronomers started using the word asteroid for the smaller bodies and then stopped naming or classifying them as planets. With the discovery of Pluto in 1930, most astronomers considered the Solar System to have nine planets, along with thousands of significantly smaller bodies (asteroids and comets). For almost 50 years Pluto was thought to be larger than Mercury, but with the discovery in 1978 of Pluto's moon Charon, it became possible to measure Pluto's mass accurately and to determine that it was much smaller than initial estimates.
Dwarf planet | History of the concept
The Committee on Small Body Nomenclature of the International Astronomical Union has not formally weighed in on any side of the debate. Instead, it has adopted the following naming convention for such objects: Befitting their centaur-like transitional orbits between TNOs and comets, "objects on unstable, non-resonant, giant-planet-crossing orbits with semimajor axes greater than Neptune's" are to be named for other hybrid and shape-shifting mythical creatures. Thus far, only the binary objects Ceto and Phorcys and Typhon and Echidna have been named according to the new policy.
Centaur (small Solar System body) | No official word, yet
An asteroseismic analysis of the residuals to the planet fit has determined that Aldebaran b has a minimum mass of Jupiter masses, and that when the star was on the main sequence it would have given this planet Earth-like levels of illumination and therefore, potentially, temperature. This would place it and any of its moons in the habitable zone.
Aldebaran | Planetary system
A Small Mahzor (Hebrew מחזור, , meaning "cycle") is a 19-year cycle in the lunisolar calendar system used by the Jewish people. It is similar to, but slightly different in usage with, the Greek Metonic cycle. Because a tropical year is 365.24219879 days, and a synodic month is 29.53058868 days, the difference between nineteen solar years and 235 lunar months is only about two hours. Thus by adding seven intercalary months in nineteen years, the solar years and the lunar years basically synchronize. Three ancient civilizations (Babylonia, China and Israel) used lunisolar calendars and knew of the rule of the intercalation from as early as 2000 BC, about the time of the biblical Tower of Babel, the confusion of language, and dispersion of nations.
Small Mahzor | Introduction
On 10 January 2012, using the Kepler Space Telescope three transiting planets were discovered in orbit around Kepler-42. These planets' radii range from approximately those of Mars to Venus. The Kepler-42 system is only the second known system containing planets of Earth's radius or smaller (the first was the Kepler-20 system pictured at left). These planets' orbits are also compact, making the system (whose host star itself has a radius comparable to those of some hot Jupiters) resemble the moon systems of giant planets such as Jupiter or Saturn more than it does the Solar System. Despite these planets' small size and the star's being one of the faintest stars in Kepler field with confirmed planets, the detection of these planets was possible due to small size of the star, causing these planets to block a larger proportion of starlight during their transits.
Kepler-42 | Planetary system
Small bodies, as primitive leftover building blocks of the Solar System formation process, offer clues to the chemical mixture from which the planets formed some 4.6 billion years ago. Current exobiological scenarios for the origin of life invoke an exogenous delivery of organic matter to the early Earth: it has been proposed that carbonaceous chondrite matter (in the form of planetesimals or dust) could have brought these complex organic molecules capable of triggering the pre-biotic synthesis of biochemical compounds on the early Earth. Moreover, collisions of NEOs with Earth pose a finite hazard to life. For all these reasons, the exploration of such objects is particularly interesting and urgent.
Hayabusa Mk2 | Scientific objectives
Theia (Θεία in Greek) or Orpheus (Ορφεύς) ) is a hypothesized ancient planet in the early Solar System that, according to the giant-impact hypothesis, collided with the early Earth around 4.5 billion years ago, with the resulting debris gathering to form the Moon. In addition to explaining Earth's large moon, the Theia hypothesis can also explain why Earth's core is larger than would be expected for a body its size; Theia's core and mantle mixed with Earth's. According to one version of the hypothesis, Theia was an Earth trojan about the size of Mars, with a diameter of about .
Theia (planet) | Introduction
Study shows that WASP-76b seems to be the only planet in its solar system.
WASP-76b | Introduction
643 Scheherezade is a minor planet orbiting the Sun. It was named after the fictional storyteller Sheherazad.
643 Scheherezade | Introduction
Earth is a wasteland after a cataclysmic solar flare and asteroid impact, which created a long impact winter and nearly made humans extinct. Some managed to survive and, with the help of a mysterious quantum computer, rebuild civilization to what it is in "Last Order". The colonization of the solar system and complex politics between the now independent colonies have left the Earth surface cut off and underdeveloped. The Scrapyard and Tiphares are found in what was once the USA (specifically the area of what is now Kansas City). Tiphares is now a big laboratory for its much more glorious sister city in space - Ketheres.
Battle Angel Alita: Last Order | Setting
In July 2008, the planet 6 Lyncis b was announced by Bun'ei Sato and collaborators from the Okayama Planet Search Program, along with 14 Andromedae b and 81 Ceti b. The planet was found to have minimum mass of 2.4 Jupiter masses and period of 899 days.
6 Lyncis | Planetary system
Mercury ( from the Sun) is the closest planet to the Sun and on average, all seven other planets. The smallest planet in the Solar System (), Mercury has no natural satellites. Besides impact craters, its only known geological features are lobed ridges or rupes that were probably produced by a period of contraction early in its history. Mercury's very tenuous atmosphere consists of atoms blasted off its surface by the solar wind. Its relatively large iron core and thin mantle have not yet been adequately explained. Hypotheses include that its outer layers were stripped off by a giant impact, or that it was prevented from fully accreting by the young Sun's energy.
Solar System | Mercury
The smallest super-Earth found as of 2008 was MOA-2007-BLG-192Lb. The planet was announced by astrophysicist David P. Bennett for the international MOA collaboration on June 2, 2008. This planet has approximately 3.3 Earth masses and orbits a brown dwarf. It was detected by gravitational microlensing. In June 2008, European researchers announced the discovery of three super-Earths around the star HD 40307, a star that is only slightly less massive than our Sun. The planets have at least the following minimum masses: 4.2, 6.7, and 9.4 times Earth's. The planets were detected by the radial velocity method by the HARPS (High Accuracy Radial Velocity Planet Searcher) in Chile.
Super-Earth | 2008
The discovery circumstances are given in the catalog of numbered minor planets.
Observations of small Solar System bodies | Introduction
The fourth episode begins at the Grand Canyon, Arizona, US, where Cox draws comparisons of the canyon to Mars and the massive Valles Marineris. A trip to Kīlauea on Hawaii shows the constant geological activity of Earth, and again a comparison to Mars and the massive Olympus Mons is seen. Both comparisons are insightful in the sense that Earth's systems are still dynamic and active whereas Mars' have gradually slowed into inactivity. Cox then switches view closer to the Sun and the scorched greenhouse planet Venus, a planet often referred to as "Earth's twin", and compares it to the vulcan geology of the Deccan Plateau.
Wonders of the Solar System | 4. "Dead or Alive"
Centaur 10199 Chariklo, with a diameter of about , is the smallest object with rings ever discovered consisting of two narrow and dense bands, 6–7 km (4 mi) and 2–4 km (2 mi) wide, separated by a gap of . The Saturnian moon Rhea may have a tenuous ring system consisting of three narrow, relatively dense bands within a particulate disk, the first predicted around a moon. Most rings were thought to be unstable and to dissipate over the course of tens or hundreds of millions of years. Studies of Saturn's rings however indicate that they may date to the early days of the Solar System.
Satellite system (astronomy) | Ring systems
It is generally thought that about 3.8 billion years ago, after a period known as the Late Heavy Bombardment, most of the planetesimals within the Solar System had either been ejected from the Solar System entirely, into distant eccentric orbits such as the Oort cloud, or had collided with larger objects due to the regular gravitational nudges from the giant planets (particularly Jupiter and Neptune). A few planetesimals may have been captured as moons, such as Phobos and Deimos (the moons of Mars) and many of the small high-inclination moons of the giant planets. Planetesimals that have survived to the current day are valuable to science because they contain information about the formation of the Solar System.
Planetesimal | Planetesimals in the Solar System
The ambiguity inherent in the IAU's definition was highlighted in December 2005, when the Spitzer Space Telescope observed Cha 110913-773444 (above), only eight times Jupiter's mass with what appears to be the beginnings of its own planetary system. Were this object found in orbit around another star, it would have been termed a planet. In September 2006, the Hubble Space Telescope imaged CHXR 73 b (left), an object orbiting a young companion star at a distance of roughly 200 AU. At 12 Jovian masses, CHXR 73 b is just under the threshold for deuterium fusion, and thus technically a planet; however, its vast distance from its parent star suggests it could not have formed inside the small star's protoplanetary disc, and therefore must have formed, as stars do, from gravitational collapse.
Definition of planet | Planetary-mass stellar objects
As of June 2016, all but one of the confirmed Kepler circumbinary planets are smaller than Jupiter. This cannot be a selection effect because larger planets are easier to detect. Simulations had predicted this would be the case.
Circumbinary planet | Planet size limit
"Pachu Pachu" - A planet ruled by large, green aliens fascinated with guns. It is verdant, with primitive villages and many plants around. The residents appear to be quite calm. (Given by Jackie's green heart) "Alamax" is a planet composed mostly of dry land. There is very little surface water and very few colonizations. What colonizations exist are fake; they are sets used to film a movie, which is what the residents appear to only do. Any visitors to the planet are taken in as part of the show. "Kleen" - The name says it all. This planet is one which is spotless and sparkling in every form.
Kaput and Zösky | Planets
Thus Ceres, at 950 km in diameter, is the smallest body for which gravitational measurements indicate current hydrostatic equilibrium. Much larger objects, such as Earth's moon, are not near hydrostatic equilibrium today, though they are primarily composed of silicate rock and iron respectively (in contrast to most dwarf planet candidates, which are ice and rock). Saturn's moons may have been subject to a thermal history that would have produced equilibrium-like shapes in bodies too small for gravity alone to do so. Thus, at present it is unknown whether any trans-Neptunian objects smaller than Pluto and Eris are in hydrostatic equilibrium.
List of possible dwarf planets | Limiting values
Besides Mana-Yood-Sushai, there are numerous other gods in Pegāna's pantheon, known as the small gods:
The Gods of Pegāna | The small gods
A is the lowest-mass planet yet discovered by any observational technique, with somewhat less than twice the mass of Earth's moon.
PSR B1257+12 | Introduction
Given a planet in a stable orbit, not too hot and not too cold, and given a few billion years of chance chemical reactions created by the interaction of a sun's energy on the planet's chemicals, it's fairly certain that life in one form or another will eventually emerge. It's reasonable to assume that there must be, in fact, countless billions of such planets where biological life has arisen, and the odds of some proportion of such life developing intelligence are high. Now, the sun is by no means an old star, and its planets are mere children in cosmic age, so it seems likely that there are billions of planets in the universe not only where intelligent life is on a lower scale than man but other billions where it is approximately equal and others still where it is hundreds of thousands of millions of years in advance of us.
Political and religious beliefs of Stanley Kubrick | Religion
Ceres (2.77 AU) is the largest asteroid, a protoplanet, and a dwarf planet. It has a diameter of slightly under , and a mass large enough for its own gravity to pull it into a spherical shape. Ceres was considered a planet when it was discovered in 1801, and was reclassified to asteroid in the 1850s as further observations revealed additional asteroids. It was classified as a dwarf planet in 2006 when the definition of a planet was created.
Solar System | Ceres
In this part, there are six gods shown praying to a sun disc at burial mounds. This is smallest portion of the Book that is known, and Part E is most likely not the beginning of the Book of the Earth.
Book of the Earth | Part E
There must be an ultimate smallness, of which there can be nothing smaller: the atomus (Leucippus, Democritus). This was in response to the Paradoxes of Zeno: there could be no motion, since every moving body would have to pass through half the distance, then one-quarter the distance, etc. A body could not pass through an infinite number of points. This led to the conclusion that all nature was united: the doctrine of the "One". Therefore, the human mind could reasonably conclude that there was a single God, and that this God existed (For an overview see Gilson p. 29-83; Russell pp.
Thought of Thomas Aquinas | Existentialism
The planet's mass has been estimated to be 8.65 times that of Jupiter, while its diameter, at , is 0.951 times Jupiter's. Its small size, despite the bloating of the planet's atmosphere, is caused by the strong gravity of the planet. This indicates its mean density is twice that of Earth and its surface gravity approximately 24 times that on Earth, almost equal to the Sun. The orbit is very eccentric, ranging from 4.90 million to 15.36 million miles from the star. In addition to heat from its primary star, tidal heating is thought to have played a significant role in this planet's evolution.
HAT-P-2b | Orbit and mass
, provisional designation , is a dark minor planet in the outer Solar System, classified as centaur, approximately 20 kilometers in diameter. The object is currently trapped in a 1:1 mean-motion resonance with Neptune following a path of the horseshoe type.
(148975) 2001 XA255 | Introduction
The system itself is estimated to be 11 billion years old, substantially older than the Solar System.
Kapteyn b | Introduction
This is the smaller world, with 0.76 Earth masses at 94% of its diameter, and 85% of its surface gravity. The mean surface temperature is only +5 °C. Because most of this chilly planet's water is locked in permafrost and glaciers, the atmosphere (which has a sea-level pressure of 0.7 bar, equivalent to about 3,650 m altitude on Earth) is not only thin but also uncomfortably dry. From the hemisphere where the companion world Genji can be seen it hangs in the sky as a globe of 6° 20' diameter, and when full gives over 320 times the light of the full Moon as seen from Earth.
Murasaki (novel) | Chujo