The planetary system has 3 prospective limits depending upon how you specify it. (Image credit: Getty Images)
The planetary system is a massive location. Our cosmic area consists of 8 worlds, around half a lots dwarf worlds, a number of hundred moons and countless asteroids and comets, all spinning around the sun– and in most cases each other– at speeds of countless miles per hour, like a huge top.
Where does it end? Well, the response might depend upon whom you ask and how they specify the planetary system.
There are not one, however 3 prospective limits to the planetary system, according to NASA: the Kuiper Belt, the ring of rocky bodies beyond the orbit of Neptune; the heliopause, the edge of the sun’s electromagnetic field; and the Oort Cloud, a far-off tank of comets that are hardly noticeable from Earth.
The arguments for each border “all have benefit,” that makes picking in between them complex, Dan Reisenfeld, a scientist at Los Alamos National Laboratory in New Mexico, informed Live Science in an e-mail.
There is one that many astronomers most typically concur upon.
Related: Have all 8 worlds ever lined up?
Kuiper Belt
The Kuiper Belt is generally comprised of asteroids. (Image credit: Getty Images)
The Kuiper Belt extends in between 30 and 50 huge systems (AU) far from the sun, according to NASA. (One huge system amounts to the range in between Earth and the sun.)
Get the world’s most interesting discoveries provided directly to your inbox.
This area is filled with asteroids and dwarf worlds, such as Pluto, that have actually been ejected from the inner planetary system by one-sided gravitational tugs-of-war with the worlds.
Some astronomers argue that the Kuiper Belt ought to be thought about the edge of the planetary system due to the fact that it loosely represents the edge of where the sun’s protoplanetary disk– the swirling ring of gas and dust that later on ended up being the worlds, moons and asteroids– would have been.
“If one directly specifies the planetary system as simply the sun and its planetary bodies, then the edge of the Kuiper Belt can be thought about to be the edge of the planetary system,” Reisenfeld stated.
This meaning of the solar system is thought about to be far too easy by some astronomers, such as Caltech’s Mike Brown.
“It’s not truly real,” Brown informed Live Science in an e-mail. “Things have actually walked around a lot– mainly outside– considering that the worlds were formed.” This implies the Kuiper Belt does not include all of the planetary system’s “things,” such as the evasive, theoretical Planet Nine, which (if it exists) most likely lies far beyond the Kuiper Belt.
In October 2023, the discovery of a lots brand-new items beyond the Kuiper Belt likewise hinted that there might be a “2nd Kuiper Belt” prowling even further out.
The unpredictability around this area’s own external edge for that reason makes it an undependable border for the planetary system as an entire,