Dwarf planets are objects in our solar system that orbit round the sun, which means they aren’t one of the eight major planets. There are five dwarf planets in our solar system that are all smaller than Mercury. Some dwarf planets have rings and moons.
What are Dwarf Planets?
In recent years, the term “dwarf planet” has become increasingly common. But what exactly is a dwarf planet? A dwarf planet is a celestial body that orbits the Sun and is massive enough to be round due to its own gravity, but has not cleared its orbital path of debris and is not a satellite. Dwarf planets are similar to regular planets in a lot of ways they’re both round and orbit the Sun but there are some key differences.
The first known dwarf planet was Ceres, which was discovered in 1801 by Giuseppe Piazzi. At the time, it was considered a planet, but as more and more objects were discovered in the same region of space (what we now know as the asteroid belt), it became clear that Ceres was very different from the other planets. In 2006, the International Astronomical Union (IAU) created a new category for celestial bodies like Ceres: dwarf planet.
There are currently five recognized dwarf planets in our Solar System: Ceres, Pluto, Haumea, Makemake, and Eris. Of these five, only one “Ceres” orbits in the inner Solar System between Mars and Jupiter. The other four all orbit in what is known as the Kuiper Belt, beyond Neptune. Most people are familiar with Pluto because it was once considered to be the ninth planet in our Solar System. However, after further study, it was reclassified as a dwarf planet in 2006
Dwarf Planets in Our Solar System
Ceres is the largest of these objects, with a diameter of about 940 kilometers. It is also the closest to the Sun, orbiting at a distance of 2.77 AU. Pluto is the second largest known dwarf planet, with a diameter of 2370 kilometers. It orbits at a distance of 39.5 AU from the Sun. Haumea is slightly smaller than Pluto, with a diameter of about 1550 kilometers. It orbits at a distance of 43.3 AU from the Sun. Make is even smaller than Haumea, with a diameter of only 1430 kilometers. Its orbit takes it out to 45.8 AU from the Sun. Finally, Eris is the smallest known dwarf planet, with a diameter of only 1160 kilometers.
However, it has the most distant orbit of any known object in our solar system, reaching out as far as 97 AU from the Sun. These five objects are all classified as dwarf planets because they meet certain criteria set forth by the International Astronomical Union (IAU). First and foremost, they must be massive enough to be rounded by their own gravity into a nearly spherical shape (like Earth or Mars), but not massive enough to clear their orbital path around the Sun (like Jupiter or Saturn). Additionally, they must not be satellites (moons) orbiting another body in our solar system.
How Many Dwarf Planets are there?
Starting around 2018, there are five formally acknowledged bantam planets in our planetary group: Ceres, Pluto, Haumea, Makemake, and Eris. There are likely many more undiscovered dwarf planets out there, especially in the far reaches of the solar system beyond Neptune.
Dwarf planets are generally much smaller than traditional planets like Earth or Jupiter. They also have a few other key characteristics that set them apart. For example, most dwarf planets have irregular shapes, and they orbit the sun at greater distances than the traditional planets do.
The discovery of additional dwarf planets is ongoing. In fact, just this year (2018), astronomers
How Big is a Dwarf Planet compared to the Earth?
A dwarf planet is a small celestial body that orbits the sun and is large enough to be spherical but has not cleared its orbital path of debris. Dwarf planets are similar in size to asteroids and comets, and they are often referred to as “mini planets.” There are five known dwarf planets in our solar system: Ceres, Pluto, Haumea, Eris, and Makemake.
Ceres is the largest dwarf planet with a diameter of about 940 kilometers (about 580 miles). This makes Ceres about 0.029 times the size of Earth. Pluto is the second largest dwarf planet with a diameter of about 2,370 kilometers (about 1,473 miles). This makes Pluto about 0.008 times the size of Earth. Haumea is the third largest dwarf planet with a diameter of about 1,960 kilometers (about 1,220 miles). This makes Haumea about 0.006 times the size of Earth.
Eris is the fourth largest dwarf planet with a diameter of about 2,326 kilometers (about 1,445 miles). This makes Eris about 0.007 times the size of Earth. Makemake is the fifth largest dwarf planet with a diameter of about 1,430 kilometers (about 896 miles). This makes Makemake about 0.004 times the size of Earth. So overall, dwarf planets are pretty small when compared to Earth!
What’s Next!
There are currently five known dwarf planets in our solar system: Ceres, Pluto, Haumea, Makemake, and Eris. However, there may be many more waiting to be discovered. In fact, astronomers believe that there could be hundreds of dwarf planets in the Kuiper Belt alone!
So, what’s next for these fascinating worlds? continued research, of course! Scientists will continue to study the dwarf planets we already know about, in hopes of learning more about their formation and evolution. And who knows? Maybe someday we’ll find even more dwarf planets lurking out there in the depths of space.