Dwarf Planets in our solar system | Makemake, Haumea, Gonggong

 What is the Dwarf Planet?

According to the International Astronomical Union, the dwarf planets are the celestial bodies that orbits the sun, has not cleared the neighborhood around its orbit, has enough mass to assume a nearly round shape and is not a moon.

The number of dwarf planets in our solar system is unknown. Now the question arises that why the Pluto is not a planet? The Pluto has enough mass to assume a nearly round shape, also orbits the sun but the Pluto has not cleared the neighborhood around its orbit. There are six known dwarf planets, the Pluto demoted as a Dwarf Planet, Eris the reason behind the demotion of the Pluto, Ceres the closest dwarf planet from the sun and from the Earth, the Makemake fourth dwarf planet, the Haumea fifth discovered dwarf planet and the Gonggong sixth dwarf planet with Chinese name. I explained the Pluto, Eris and Ceres in my previous article.

1] Makemake dwarf planet

            The Makemake is the second brightest object in the Kuiper belt after Pluto. Makemake was the fourth body identified as a dwarf planet and was one of the bodies that caused Pluto to lose its status as a Planet. The dwarf planet Makemake was discovered in the outer solar system in March 31, 2005 by M.E. Brown, D. Rabinowitz and C.A. Trujillo at the Palomar observatory. The dwarf planet Makemake was named after the Rapanui god of fertility. The Makemake is a member of a Kuiper belt which is a group of objects that orbit in a disc like zone beyond the orbit of the Neptune.

The Makemake Dwarf Planet

            The Makemake is slightly smaller than the Pluto. The diameter of Makemake is approximately 888 miles or 1430 km. It has average orbital speed of 4.4 km per second and it required 305 Earth years to complete one trip around the Sun. The distance between the sun and Makemake is 38 AU, when it was closest to the sun and the distance 52.76 AU when it was farthest from the sun. The orbit of the Makemake is highly inclined at 29^o to the plane of the solar system. But its orbit remains stable because its orbit lies far enough from the Neptune. The day on the Makemake is approximately 23 hours long. This rotational period is relatively long for a dwarf planet. This long rotational period may be due to tidal acceleration from satellite of Makemake. Makemake has one discovered moon.  The moon named as S/2015 (136472) 1 and nicknamed as MK2. The MK2 is 13,000 miles away from the Makemake.

2] Haumea dwarf planet

            The Haumea is the officially the fifth dwarf planet, the four dwarf planet came before it is Pluto, Eris, Cere and Makemake. The Haumea is another dwarf planet located beyond the orbit of the Neptune. The Haumea is known for its very small rotational period. The rotational period of the Haumea is only 4 hours approximately as predicted by the scientists. The Haumea is named after the Hawaiian goddess of the childbirth on September 17, 2008. The Haumea was discovered in 2004 by Mike Brown’s team of Caltech at the Palomar Observatory in United States and independently in 2005 by Jose Luis Ortiz Moreno’s team at the Sierra Nevada Observatory in Spain.

The Haumea Dwarf planet

            The Haumea has an unusual shape like a stretched football. The Haumea is fastest rotating object in our solar system. Because of this rotation, the Haumea will get shape as dumbly in near future. The longest diameter of Haumea is approximately 1960 km. According to scientists, Haumea collided with another large object in this past. This collision might have knocked away most of light weight ice of Haumea, leaving heavier rock behind. Because of this the Haumea is the rocky and coated with the ice. In 2017, the scientists observed the ring around the Haumea. So, Haumea is the first Trans-Neptunian Object that has a ring. The radius of the ring (from the center of the Haumea) is approximately 2287 km and approximately 70 km wide with nearly 3.2^o inclination.

            The requires 284 Earth years to complete one trip around the Sun. The closest distance between the Sun and the Haumea is 35 AU (Perihelion) and the longest distance between them is 52 AU (Aphelion). The Haumea orbits the Sun with an average orbital speed of 4.5 km per second. The orbital inclination of Haumea with the plane of the solar system is approximately 28^o. In 2005, two small satellites have been discovered orbiting the Haumea. The two satellites are Hi’iaka and Namaka. Hi’iaka is the outer satellite of the Haumea and the Namaka is the smaller, inner satellite of the Haumea.

3] Gonggong dwarf planet

            The dwarf planet Gonggong is the member of the scattered disc beyond the orbit of the Neptune. It is sixth farthest known solar system object. The Gonggong was discovered in July 2007 by American astronomers at the Palomar Observatory. And the discovery was announced in January 2009. The name of this dwarf planet is chosen from an online poll hosted by the discoverers of the Gonggong. The name Gonggongis given after a water god in Chinese mythology. The Gonggong has a one known moon and is named Xiangliu, after the minister that attended to the deity in Chinese folklore. The dwarf planet Gonggong and its moon both the bodies are the first major solar system bodies to have Chinese names. According to Chinese mythology the Gonggong was a short-tempered god who always creates leading to floor, chaos and landslides.

The Gonggong dwarf planet

            The Gonggong is approximately the size of the Pluto’s moon Charon. It is the fifth largest known Trans-Neptunian Object. The Gongong may be sufficient massive to be gravitationally rounded in shape and this is the reason that the Gonggong is categorised as a dwarf planet. The surface of Gonggong is appears red, likely due to the presence of organic compounds called tholins. Water ice is also present on the surface of Gonggong, which hints at a brief period of cryovolcanic activity in the distant past.

            The Gonggong orbits the Sun at an average distance of nearly 68 AU. And it requires 554 Earth years to complete one trip around the Sun. The orbital path of the Gonggong is highly inclined. The inclination is 30.7^o to the plane of the solar system. The distance between the Gonggong and the Sun, when Gonggong is closest to the Sun is approximately 33.8 AU and distance when it is farthest from the Sun is approximately 101.2 AU. The diameter of the Gonggong is derived from radiometric measurements is of 1230 km or 760 miles. The one day on the Gonggong is nearly 22 hours long. This is very slow rotational period as compared with other Trans-Neptunian Object. This is very slow rotational period of Gonggong is because of the tidal force of its moon, Xiangliu. The Gonggong has a large mass. This large mass makes retention of a tenuous atmosphere of methane. But such an atmosphere would slowly escspe into space.