Fifth planet (hypothetical)
Hypothetical former fifth planet between Mars and Jupiter.
In the history of astronomy, several hypothetical planets have been proposed to have once existed between Mars and Jupiter. These hypothetical bodies, often referred to as a fifth planet, have been invoked to explain characteristics of the inner Solar System, such as the asteroid belt or the Late Heavy Bombardment. While none have been confirmed, they have played a role in scientific debate and science fiction.
- field
- Astronomy
- known_for
- Hypothetical former fifth planet between Mars and Jupiter
- hypotheses
- Disruption hypothesis (Phaeton), Planet V hypothesis, fictional Bodia
Lore & Background
Three main ideas have been proposed regarding hypothetical planets between Mars and Jupiter. The disruption hypothesis, first proposed by astronomer Heinrich Wilhelm Matthias Olbers, suggested that a planet once positioned between Mars and Jupiter was destroyed, creating the asteroid belt. This hypothetical planet was dubbed 'Phaeton' by 20th-century scientists, with proposed masses ranging from 1 to 8 lunar masses and an icy composition. However, the hypothesis faced criticisms due to difficulties in explaining planetary breakup and was eventually superseded by the accretion model, as the asteroid belt's properties did not fit a single disrupted planet.
Reader's Guide
The concept of a hypothetical fifth planet has been significant in both scientific and cultural contexts. Scientifically, it has prompted hypotheses to explain the asteroid belt and the Late Heavy Bombardment, though none have been confirmed. The disruption hypothesis (Phaeton) was an early attempt to account for the asteroid belt but was later replaced by the accretion model. The Planet V hypothesis offered a different explanation for the Late Heavy Bombardment, linking it to an unstable planet that crashed into the Sun. These ideas illustrate the evolving nature of planetary science and the role of hypothetical models in understanding Solar System history. Culturally, the destroyed fifth planet has been a recurring theme in science fiction, especially after the invention of the atomic bomb, serving as a cautionary tale about nuclear weapons. Though largely relegated to retro works, it remains a notable element in the history of astronomical speculation.
Did You Know?
- The disruption hypothesis was first proposed by astronomer Heinrich Wilhelm Matthias Olbers.
- The hypothetical planet Phaeton was proposed to have masses ranging from 1 to 8 lunar masses.
- NASA scientists John Chambers and Jack J. Lissauer proposed Planet V, which they claim most probably crashed into the Sun.
- In fiction, the hypothetical fifth planet is often called 'Bodia' after Johann Elert Bode.
More in Hypothetical astronomical objects 1-24
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