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Based on a careful study of Saturn's orbit and using mathematical models, French scientists were able to whittle down the search region for Planet Nine to "possible" and "probable" zones. Source: CNRS, Cote d'Azur and Paris observatories. Credit:
An imagined view from Planet Nine looking back toward the Sun. Astronomers think the massive, distant planet is gaseous, similar to the other giant planets in our Solar System. Credit: Wikipedia
Last month, planetary scientists Mike Brown and Konstantin Batygin of the California Institute of Technology found evidence of a giant planet tracing a bizarre, highly elongated orbit in the outer Solar System. Nicknamed Planet Nine, it’s estimated to be 10 times more massive than Earth with a diameter as large as 16,000 miles (25,750 km). The putative planet orbits about 20 times farther from the Sun on average than Neptune or some 56 billion miles away; at that tremendous distance it would take between 10,000 and 20,000 years to complete one orbit around the Sun.
The six most distant known objects in the Solar System with orbits exclusively beyond Neptune (magenta) all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Batygin and Brown showed that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC); Diagram created using WorldWide TelescopePlanet Nine’s existence is inferred through mathematical modeling and computer simulations based on the clustering of six remote asteroids in the Kuiper Belt, a vast repository of icy asteroids and comets beyond Neptune. Brown and Batyginsay there’s only a 0.007% chance or about 1 in 15,000 that the clustering could be a coincidence.
All well and good. But with such an enormous orbit, astronomers face the daunting task of searching vast swaths of space for this needle in a haystack. Where to begin? A study done by a team of French scientists may help narrow the search. In a recent paper appearing in Astronomy and Astrophysics, astronomerAgnes Fienga and colleagues looked at what effect a large Kuiper Belt planet would have on the orbits of other planets in the Solar System, focusing their study on Saturn. Thanks to NASA’s Cassini orbiter, which has been orbiting Saturn since 2004, we can precisely calculate Saturn’s position along its orbit.
Based on a careful study of Saturn’s orbit and using mathematical models, French scientists were able to whittle down the search region for Planet Nine to “possible” and “probable” zones. Source: CNRS, Cote d’Azur and Paris observatories , created by the author
Based on the planet’s “residuals”, the difference between the calculated position of Saturn versus what was actually observed, the team was able to exclude two sections of its potential orbit and home in on “probable” swath and a much larger “possible” section of the orbit. The process may sound familiar, since it was the one used to discover another planet more than 150 years ago — Neptune. Back then, irregularities (residuals) in the motion of Uranus led astronomers in 1847 to predict a more distant 8th planet as the cause. On September 24, 1846, Johann Galle discovered Neptune only 1° from its position predicted by French mathematician Urbain LeVerrier.
While the current solution for Planet Nine doesn’t come anywhere near as close, it’s a step in the right direction.
The waning crescent Moon above Venus and Saturn (dimmer and below Venus) in the dawn twilight on January 6, 2016. The Moon re-visits the grouping in early February. Image credit and copyright: Alan Dyer.
A fine sight greets early risers this week into the month of February, as all five naked eye planets: Mercury, Venus, Mars, Saturn and Jupiter ring the sky from horizon to horizon.
Though not a true planetary alignment as extolled by many websites, this is a great chance to see all five classical planets above the horizon at once… or seven, if you count the waning gibbous Moon and the rising Sun, as the ancients did as part of their geocentric, Earth-entered universe. You can kinda see how they got there, as the very heavens themselves seemed to whorl about the cradle of earthly human affairs. Continue reading “And Mercury Makes Five: See All Naked Eye Planets in the Sky at Once”
Artist's concept of the hypothetical "Planet Nine." Could it have moons? Credit: NASA/JPL-Caltech/Robert Hurt
Artistic rendering shows the distant view from theoretical Planet Nine back towards the sun. The planet is thought to be gaseous, similar to Uranus and Neptune. Hypothetical lightning lights up the night side. Credit: Caltech/R. Hurt (IPAC)
The astronomer known worldwide for vigorously promoting the demotion of Pluto from its decades long perch as the 9th Planet, has now found theoretical evidence for a new and very distant gas giant planet lurking way beyond Pluto out to the far reaches of our solar system.
![The six most distant known objects in the solar system with orbits exclusively beyond Neptune (magenta) all mysteriously line up in a single direction. Also, when viewed in three dimensions, they tilt nearly identically away from the plane of the solar system. Batygin and Brown show that a planet with 10 times the mass of the earth in a distant eccentric orbit anti-aligned with the other six objects (orange) is required to maintain this configuration. Credit: Caltech/R. Hurt (IPAC); [Diagram created using WorldWide Telescope.]](https://www.universetoday.com/wp-content/uploads/2016/01/Planet-nine.jpg)
