Planet V
Encyclopedia
Planet V is a hypothetical
fifth planet posited by NASA
scientists John Chambers and Jack Lissauer to have once existed between Mars
and the asteroid belt
, based on computer simulations. Chambers and Lissauer presented this idea during the 33rd Lunar and Planetary Science Conference
, held from March 11 through 15, 2002.
Chambers and Lissauer proposed that a previously unknown terrestrial planet
once existed in an eccentric and unstable orbit
around the Sun
, at least 4 Ga (four billion years) ago. They connect this planet, which they name Planet V, and its disappearance with the Late Heavy Bombardment
episode of the Hadean
era.
"The extra planet formed on a low-eccentricity orbit
that was long-lived, but unstable," Chambers reported. About 3.9 billion years ago, Planet V was perturbed by gravitation
al interactions with the other inner planets. It was tossed onto a highly eccentric orbit that crossed the inner asteroid belt, a reservoir of material much larger than it is today. It spun through the inner belt of asteroid
s, causing them to fly into Mars-crossing orbits
. This temporarily enhanced the population of bodies on Earth-crossing orbits
, and also increased the lunar impact rate.
According to Chambers, Planet V is thought to have perished when it plunged into the Sun.
Hypothetical planet
A hypothetical Solar System object is a planet, natural satellite or similar body in our Solar System whose existence is not known, but has been inferred from observational scientific evidence. Over the years a number of hypothetical planets have been proposed, and many have been disproved...
fifth planet posited by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
scientists John Chambers and Jack Lissauer to have once existed between Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
and the asteroid belt
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
, based on computer simulations. Chambers and Lissauer presented this idea during the 33rd Lunar and Planetary Science Conference
Lunar and Planetary Science Conference
The Lunar and Planetary Science Conference , jointly sponsored by the Lunar and Planetary Institute and NASA Johnson Space Center , brings together international specialists in petrology, geochemistry, geophysics, geology and astronomy to present the latest results of research in planetary science...
, held from March 11 through 15, 2002.
Chambers and Lissauer proposed that a previously unknown terrestrial planet
Terrestrial planet
A terrestrial planet, telluric planet or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun...
once existed in an eccentric and unstable orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
around the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, at least 4 Ga (four billion years) ago. They connect this planet, which they name Planet V, and its disappearance with the Late Heavy Bombardment
Late Heavy Bombardment
The Late Heavy Bombardment is a period of time approximately 4.1 to 3.8 billion years ago during which a large number of impact craters are believed to have formed on the Moon, and by inference on Earth, Mercury, Venus, and Mars as well...
episode of the Hadean
Hadean
The Hadean is the geologic eon before the Archean. It started with the formation of the Earth about 4.7 Ga and ended roughly 3.8 Ga, though the latter date varies according to different sources. The name "Hadean" derives from Hades, Greek for "Underworld", referring to the "hellish"...
era.
"The extra planet formed on a low-eccentricity orbit
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
that was long-lived, but unstable," Chambers reported. About 3.9 billion years ago, Planet V was perturbed by gravitation
Gravitation
Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...
al interactions with the other inner planets. It was tossed onto a highly eccentric orbit that crossed the inner asteroid belt, a reservoir of material much larger than it is today. It spun through the inner belt of asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s, causing them to fly into Mars-crossing orbits
Mars-crosser asteroid
A Mars-crosser is an asteroid whose orbit crosses that of Mars. The known numbered Mars-crossers are listed here. They include the two numbered Mars trojans 5261 Eureka and ....
. This temporarily enhanced the population of bodies on Earth-crossing orbits
Earth-crosser asteroid
An Earth-crosser is a near-Earth asteroid whose orbit crosses that of Earth as observed from the ecliptic pole of Earth's orbit. The known numbered Earth-crossers are listed here. Those Earth-crossers whose semi-major axes are smaller than Earth's are Aten asteroids; the remaining ones are Apollo...
, and also increased the lunar impact rate.
According to Chambers, Planet V is thought to have perished when it plunged into the Sun.
See also
- Phaeton (hypothetical planet)Phaeton (hypothetical planet)Phaeton is the name of a hypothetical planet posited to once have existed between the orbits of Mars and Jupiter whose destruction supposedly led to the formation of the asteroid belt...
- Fifth planet (hypothetical)Fifth planet (hypothetical)In the history of astronomy, a handful of solar system bodies have been counted as the fifth planet from the Sun. Under the present definition of a planet, this celestial body is Jupiter.-Previous fifth planets:...
- List of hypothetical solar system objects