Dwarf planets

October 27, In recent years, there's been a lot of hubbub about Pluto losing its status as one of the planets of the solar system. Pluto is no longer considered the ninth planet in the series of major planetary objects, but instead is now just one of the many so-called "dwarf planets. As ofdelegates from the mission are trying to get Pluto's planethood status back.

Dwarf planets

The term dwarf planet has been tossed around a lot in recent years. As part of a three-way categorization of bodies orbiting the Sun, the term was adopted in due to the discovery of objects beyond the orbit of Neptune that were comparable in size to Pluto.

Since then, it has come to be used to describe many objects in our Solar System, upending the old classification system that claimed there were nine planets. The term has also led to its fair share of confusion and controversy, with many questioning its accuracy and applicability to bodies like Pluto.

Nevertheless, the IAU currently recognizes five bodies within our Solar System as dwarf planets, six more could be recognized in the coming years, and as many as or more could exist within the expanse of the Kuiper Belt.

More explicitly, it has to have sufficient mass to overcome its compressive strength and achieve hydrostatic equilibrium. For one, it must be in direct orbit of the Sun and not be a moon around another body.

Second, it must be massive enough for it to have become spherical in shape under its own gravity. And, unlike a planet, it must have not cleared the neighborhood around its orbit.

Dwarf planets

The largest known trans-Neptunian objects TNOshown to scale. Brown Size and Mass: In order for a body to be become rounded, it must be sufficiently massive, to the point that its own gravity is the dominant force effecting it.

Dwarf Planets: Science and Facts About Solar System’s Smaller Worlds

Here, the internal pressure created by this mass would cause a surface to achieve plasticity, allowing high elevations to sink and hollows to fill in.

This does not occur with smaller bodies that are less than a few km in diameter such as asteroidswhich are dominated by forces outside of their own gravity forces and tend to maintain irregular shapes.

The bigger the body is, the higher its internal pressure, until the pressure is sufficient to overcome its internal compressive strength and it achieves hydrostatic equilibrium.

At this point, a body is as round as it can possibly be, given its rotation and tidal effects. This is the defining limit of a dwarf planet. However, rotation can also affect the shape of a dwarf planet. If the body does not rotate, it will be a sphere.

But the faster it does rotate, the more oblate or even scalene it becomes. The extreme example of this is Haumeawhich is twice as long along its major axis as it is at the poles. An extreme example of this is the Pluto-Charon system, where both bodies are tidally locked to each other.

The upper and lower size and mass limits of dwarf planets have not been specified by the IAU. And while the lower limit is defined as the achievement of a hydrostatic equilibrium shape, the size or mass at which an object attains this shape depends on its composition and thermal history.

For example, bodies made of rigid silicates such as rocky asteroids should achieve hydrostatic equilibrium at a diameter of approx. As a result, no specific standard currently exists for defining a dwarf planet based on either its size or mass, but is instead more generally defined based on its shape.

In short, planets are able to remove smaller bodies near their orbits by collision, capture, or gravitational disturbance or establish orbital resonances that prevent collisionswhereas dwarf planets do not have the requisite mass to do this. To calculate the likelihood of a planet clearing its orbit, planetary scientists Alan Stern and Harold F.

Levison the former of whom is the principal investigator of the New Horizons mission to Pluto and the Chief Scientist at Moon Express introduced a parameter they designated as?

Astronomers like Steven Soter, the scientist-in-residence for NYU and a Research Associate at the American Museum of Natural History, have advocated using this parameter to differentiate between planets and dwarf planets.

Recognized and Possible Dwarf Planets: There are currently five dwarf planets: PlutoErisMakemakeHaumeaand Ceres.Dwarf Planets of the Solar System. This page provides a brief description of each of the dwarf planets of our solar system.

Solar System Map - showing size, mass and orbital period, and orbit scale of planets & dwarf planets Although classified as a dwarf planet, it is quite small with a diameter less than a third that of the Moon, and a.

Eyes on the Solar System lets you explore the planets, their moons, asteroids, comets and the spacecraft exploring them from to Ride with the Curiosity Rover as it lands on Mars or fly by Pluto with the New Horizons spacecraft all from the comfort of your home computer.

There are 5 officially recognised dwarf planets in our solar system, they are Ceres, Pluto, Haumea, Makemake and Eris. With the exception of Ceres, which is located in the asteroid belt, the other dwarf planets are found in the outer solar system.

List of possible dwarf planets - Wikipedia

Pluto was once a planet and was the 9th planet in the solar system until it was found to be a dwarf planet instead. Pluto is the largest of the dwarf planets and has 5 moons. Haumea is the 3rd closest dwarf planet to the sun and lives in the Kuiper belt.

Dwarf Planet Facts There are 5 officially recognised dwarf planets in our solar system, they are Ceres, Pluto, Haumea, Makemake and Eris. With the exception of Ceres, which is located in the asteroid belt, the other dwarf . Dwarf planets pass the first two tests but flunk the third: They share their region of the solar system with other objects like them, so they lack the uniqueness of Earth or Mars.

Dwarf planets
Dwarf Planets: Science and Facts About Solar System’s Smaller Worlds