Phaeton (alternativelyPhaethon/ˈfeɪ.əθən/ orPhaëton/ˈfeɪ.ətən/; fromAncient Greek:Φαέθων,romanized: Phaéthōn,pronounced[pʰa.é.tʰɔːn]) is ahypothetical planet hypothesized by theTitius–Bode law to have existed between theorbits ofMars andJupiter, the destruction of which supposedly led to the formation of theasteroid belt (including thedwarf planetCeres). The hypothetical planet was named forPhaethon, the son of the sun godHelios inGreek mythology, who attempted to drive his father's solar chariot for a day with disastrous results and was ultimately destroyed byZeus.[1]
According to the hypothesizedTitius–Bode law proposed in the 1700s to explain the spacing of planets in a solar system, a planet may have once existed between Mars and Jupiter. After learning of the regular sequence discovered by the German astronomer and mathematicianJohann Daniel Titius, astronomerJohann E. Bode urged a search for the fifth planet corresponding to a gap in the sequence.(1) Ceres, the largestasteroid in the asteroid belt (now considered adwarf planet), was serendipitously discovered in 1801 by the ItalianGiuseppe Piazzi and found to closely match the "empty" position inTitius' sequence, which led many[who?] to believe it to be the "missing planet". However, in 1802astronomerHeinrich Wilhelm Matthäus Olbers discovered and named the asteroid(2) Pallas, a second object in roughly the same orbit as (1) Ceres.
Olbers proposed that these two discoveries were the fragments of adisrupted planet that had formerly orbited the Sun,[2] and predicted that more of these pieces would be found. The discovery of the asteroid(3) Juno byKarl Ludwig Harding and(4) Vesta by Olbers, buttressed his hypothesis. In 1823, German linguist and retired teacherJohann Gottlieb Radlof [de] called Olbers' destroyed planetPhaëthon, linking it to theGreek myths and legends aboutPhaethon and others.[3]
In 1927,Franz Xaver Kugler wrote a short book titledSibyllinischer Sternkampf und Phaëthon in naturgeschichtlicher Beleuchtung (The Sybilline Battle of the Stars and Phaeton Seen as Natural History).[4][5] The central idea in Kugler's book is that the myth of Phaethon was based on a real event: Making use of ancient sources, Kugler argued that Phaeton had been a very bright celestial object that appeared around 1500 BC which fell toEarth not long afterwards as a shower of large meteorites, causing catastrophic fires and floods in Africa and elsewhere.[citation needed]
Hypotheses regarding the formation of the asteroid belt from the destruction of a hypotheticalfifth planet are today collectively referred to as "the disruption theory". These hypotheses state that there was once a major planetary member of theSolar System circulating in the present gap between Mars and Jupiter, which was destroyed by one or more of the following hypothetical processes:[citation needed]
In 1953, Soviet Russian astronomerIvan I. Putilin suggested that Phaeton was destroyed due tocentrifugal forces, giving it a diameter of approximately 6,880 kilometres (4,280 mi) (slightly larger than Mars' diameter of 6,779 kilometres [4,212 mi]) and a rotational speed of 2.6 hours. Eventually, the planet became so distorted that parts of it near its equator were spun off into space.Outgassing of gases once stored in Phaeton's interior caused multiple explosions, sending material into space and formingasteroid families. However, his hypothesis was not widely accepted. Two years later in 1955,Odesan astronomerKonstantin N. Savchenko suggested that Ceres, Pallas, Juno, and Vesta were not fragments of Phaeton, but rather its former moons. Phaeton had an additional fifth satellite, assumed to be the size of Ceres, orbiting near the planet'sHill sphere, and thus more subject to gravitational perturbations from Jupiter. As a result, the fifth satellite became tidally detached and orbited the Sun for millions of years afterward, making periodic close misses with Phaeton that slowly increased its velocity. Once the escaped satellite re-entered Phaeton's Hill sphere, it collided with the planet at high speed, shattering it while Ceres, Pallas, Juno, and Vesta assumed heliocentric orbits. Simulations showed that for such a Ceres-sized body to shatter Phaeton, it would need to be travelling at nearly 20 kilometres per second (12 mi/s).[6]
The disrupted planet hypothesis was also supported by French–Italian mathematician and astronomerJoseph-Louis Lagrange in 1814;[7] Canadian geologistReginald Daly in 1943;[8] American geochemistsHarrison Brown andClair Patterson in 1948;[9] Soviet academicsAlexander Zavaritskiy in 1948,Vasily Fesenkov in 1950 (who later rejected his own model) andOtto Schmidt (died 1956);[6] British–Canadian astronomerMichael Ovenden in 1972–1973;[10][11] and American astronomerDonald Menzel (1901–1976) in 1978.[12] Ovenden suggested that the planet be named "Krypton" after the destroyed native world ofSuperman, as well as believing it to have been agas giant roughly eighty-five to ninetyEarth masses in mass and nearly the size ofSaturn.[10]
Today, the Phaeton hypothesis has beensuperseded by theaccretion model.[13] Most astronomers today believe that the asteroids in the main belt are remnants of theprotoplanetary disk that never formed a planet and that in this region the amalgamation of protoplanets into a planet was prevented by the disruptive gravitational perturbations of Jupiter during the formative period of theSolar System.[citation needed]
Some scientists and non-scientists continue to advocate for the existence and destruction of a Phaeton-like planet.
Zecharia Sitchin suggested that the goddess known to the Sumerians asTiamat in fact relates to a planet that was destroyed by arogue planet known asNibiru, creating both Earth and the asteroid belt.[14] His work is widely regarded aspseudoscience.[15]
The astronomer and authorTom Van Flandern held that Phaeton (which he called "Planet V", with V representing the Roman numeral for five and not to be confused with theother postulated former fifth planet not attributed to the formation of the asteroid belt) exploded through some internal mechanism. In his "Exploded Planet Hypothesis 2000", he lists possible reasons for its explosion: a runaway nuclear reaction of uranium in its core, a change of state as the planet cooled down creating a density phase change, or through continual absorption of heat in the core fromgravitons. Van Flandern even suggested that Mars itself may have been a moon of Planet V, due to its craters hinting to exposure to meteorite storms and its relatively low density compared to the other inner planets.[16][17][18]
In 1972,Soyuzmultfilm studios produced an animatedshort film titledPhaeton: The Son of Sun (Russian:Фаэтон – Сын Солнца), directed byVasiliy Livanov, in which the asteroid belt is portrayed as the remains of a planet. The film also has numerous references toancient astronauts.[19][20]
The hypothetical former fifth planet has been referenced in fiction since at least the late 1800s.[21][22] Inscience fiction, the planet is often called "Bodia" afterJohann Elert Bode.[22][23] By thepulp era of science fiction, Bodia was a recurring theme. In these stories it is typicallysimilar to Earth and inhabited by humans, often advanced humans and occasionally the ancestors of humans on Earth.[24][23][25][26] Following the invention of theatomic bomb in 1945, stories of this planetary destruction became increasingly common, encouraged by the advent of a plausible-seeming means of disintegration.[27] Several works of the 1950s used the idea to warn of the dangers of nuclear weapons.[21][22][28] The concept has since largely been relegated to deliberately retro works.[29]
Olbers fleshed out the idea in a letter to William Herschel on May 17, 1802:
How might it be if Ceres and Pallas were just a pair of fragments, or portions of a once greater planet which at one time occupied its proper place between Mars and Jupiter, and was in size more analogous to the other planets, and perhaps millions of years ago, had, either through the impact of a comet, or from an internal explosion, burst into pieces?
Presque toutes ces petites planètes circulent entre les orbites de Mars et Jupiter. On admet qu'elles représentent les fragments dispersés d'une grande planète qui se serait désintégrée [inter alia]
The "science" in science-fiction of the Gernsback period was not wholly borrowed from the outside world. Some concepts were created on a mythical level. [...] Particularly interesting is the establishment of "Bodia" (according to one cosmology of the day, a former fifth planet whose destruction formed the asteroids) as the ultimate origin of mankind and possessor of a supercivilization.
Bode's Fifth Planet, "Bodia." (A hypothetical planet between Mars and Jupiter that broke up to form the asteroid belt. It is usually fictionally considered as Earth-like, with a human population.)
