5 Dwarf Planets in the Solar System

Dwarf planets are celestial bodies that are almost similar to ordinary planets. There are three conditions for a celestial body to be called a dwarf planet.


The conditions are that it orbits around the Sun, has sufficient mass and has its own gravity, is almost spherical in shape, is not a satellite, and has not cleared the area around its orbit.


Reporting from Space Facts, there are 5 dwarf planets in our solar system. Here's the explanation.

1. Ceres

Ceres Planet is the closest dwarf planet to the Sun. This planet is located in the asteroid belt between Mars and Jupiter. Ceres is the smallest dwarf planet among the five planets that will be discussed. Its diameter is only 950 kilometers. Ceres was first discovered in 1801 by the Italian astronomer Giuseppe Piazzi. Initially, Ceres was considered an ordinary asteroid. It was only in 2006, Ceres was classified as a dwarf planet. In 2015, NASA managed to visit this first dwarf planet. Another uniqueness is that Ceres is the only small planet that does not have a moon or natural satellite.

Dwarf Planet Ceres between Mars and Jupiter This Hides Ocean World

The dwarf planet is known to be a barren space rock, but discoveries from a recent major exploratory mission suggest the existence of an oceanic world on the planet.

As quoted from The Guardian, Friday (14/8/2020), researchers found a reservoir of seawater beneath the surface of the largest object in the asteroid belt between Mars and Jupiter.

A team of scientists from the United States and Europe, has now analyzed the images captured by the space agency NASA Dawn.

The image was delivered from the orbiter, which was taken about 35 km from the asteroid. They focused on the 20-million-year-old Occator crater and determined that there is a "vast reservoir" of salt water beneath its surface.

Several studies published in the journal Nature Astronomy, Nature Geoscience and Nature Communications also shed more light on the dwarf planet discovered by the Italian polymath Giuseppe Piazzi in 1801.

The team used infrared imaging and found the presence of hydrohalite compounds, which are materials commonly found in sea ice. However, it has not currently been observed outside Earth.

Maria Cristina De Sanctis, Istituto Nazionale di Astrophysica, Rome says hydrohalite is a clear sign that Ceres used to have seawater.

"Now we can say that Ceres is an oceanic world, like some of the moons of Saturn and Jupiter," De Sanctis said.

The research team also revealed the presence of salt deposits that appear to have accumulated in the last 2 million years. This suggests that saltwater may still be rising from the planet's interior, something De Sanctis called could have profound implications in future research.

"The material found at Ceres is very important in astrobiology, because all these minerals are essential for the emergence of life," explains De Sanctis.

2. Pluto

Pluto was discovered in 1930 and is the second closest small planet to the Sun. Initially, Pluto was referred to as the ninth planet. However, this was revised in 2006 along with the planet Ceres. Pluto is the largest dwarf planet with a diameter of 2,372 kilometers. Pluto has 5 moons, each named Charon, Hydra, Nix, Kerberos, and Styx. One-third of Pluto is water, while the rest is rock. The surface is covered with ice, mountains and valleys. Pluto is the second dwarf planet that NASA's spacecraft managed to visit in 2006.

3. Haumea

Haumea is the third closest dwarf planet from the Sun. Uniquely, this planet is oval in shape. Due to its unique shape, a day in Haumea only lasts 3.9 hours. In 2009 observations, there was a dark red dot on its surface. The researchers suspect this is the result of high levels of minerals and carbon on the Haumea ice surface.

4. Makemake

Makemake was first discovered on March 31, 2005. The diameter of this planet is 1,434 kilometers. Makemake has one moon which is named MK 2. The diameter of MK 2 is only 160 kilometers.

5. Eris

This is a dwarf planet farthest from Earth with the greatest mass. This planet was once thought to be the tenth planet because of its size. Unfortunately, according to the International Astronomical Union ((IAU)), the planet is not yet large enough. Therefore in 2006 it was decided that this is a dwarf planet. Eris was discovered in 2005 in the Kuiper Belt along with Pluto. The diameter of this planet is almost the same as Pluto, which is 2,326 kilometers.

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