The Dwarf PLANETS of the solar system

The term dwarf planet It has become very well known and is very controversial, but what is a dwarf planet? What makes a planet, like Pluto, go from being a planet to being a dwarf planet? Are there more planets like Pluto in the Solar System? If you want to know more about dwarf planets, what are the dwarf planets of the Solar System and many curious facts about them, we invite you to continue reading this lesson from a TEACHER!

Index

1. What is a dwarf planet: Easy definition
2. The 5 dwarf planets of the Solar System
3. Eris, one of the dwarf planets of the solar system
4. Pluto
5. Makemake
6. Haumea
7. Ceres, another of the dwarf planets of the solar system

In 2006 a reclassification of the planets of our Solar systemand the term was first introduced dwarf planet. The International Astronomical Union (IAU) on August 24, 2006, defined dwarf planets as celestial bodies that, despite rotating around the Sun, have enough mass to create their own gravity, be almost spherical in shape and not be the satellite of another planet or other non-stellar body, they are not alone in their orbit close.

The definition of dwarf planet is, therefore, that of a celestial body that:

• Orbit around a star (in the case of the Solar System, around the Sun).
• It has enough mass for its own gravity and has overcome the rigid body force. This translates into acquiring a hydrostatic balance that allows it to have an almost spherical shape.
• It is not a satellite of a planet or other non-stellar body.
• It has not cleared the vicinity of its orbit.

What are the differences between a planet and a dwarf planet?

By this definition, the biggest difference between a planet and a dwarf planet is that dwarf planets have not cleared their close orbit, that is, around it there is another case of large bodies, which suggests a different origin for the two types of bodies.

Accompanying this new classification, the concept of plutoid. This is the name given to a celestial object that meets the definition of dwarf planet and also belongs to the group of trans-Neptunians (Its orbit is partially or totally beyond the orbit of the planet Neptune).

Image: Slideshare

We are going to talk about the dwarf planets of the solar system. The most immediate and media consequences of this new IAU planet definition were Pluto's loss of planet status.Pluto it was classified as a dwarf planet. On the other hand, other celestial bodies "rose in category" and were included in this new group: Ceres, previously considered an asteroid, became a dwarf planet. Eris (known as Xena informally), Makemake Y Haumea they also became part of the group of dwarf planets.

Currently, in the Solar System we find five dwarf planets:

1. Pluto
2. Ceres
3. Eris
4. Makemake
5. Haumea

But there is a long list of celestial bodies candidates to be dwarf planets. A lot of cubewano u "classic Kuiper belt objects", like Varuna or Quaoar, are considered possible dwarf planets. It is also a possible dwarf planet Charon, which is currently considered a satellite of Pluto.

Pluto and Charon they orbit around a point in space between them without that point being inside Pluto. Until now, it was considered that Charon was a satellite of Pluto because it was even smaller than this, but now, Charon also meets the definition of a dwarf planet. Also, there is no clear definition of what constitutes a satellite and what a binary system or double planet system. If we look at the new classification, Pluto and Charon would be a system of double planets and Charon would also become a dwarf planet.

In conclusion, it is still not clear which are the planets of the Solar System, what is clear is that this list will grow in the following years.

Eris is he dwarf planet farthest from the Sun. It was discovered in January 2005 and is located 96.4 Astronomical Units (AU) from the Sun, that is, almost 14 billion km from the Sun. In addition, it is the greater mass, the second in size (after Pluto) and the largest body in the solar system that has not been visited by a space probe.

At first, Eris appeared to be larger than Pluto, which is why NASA initially considered it as the 10th planet in the solar system, like its discoverers and the media. This discovery motivated the International Astronomical Union (IAU) to define the term "planet" and "dwarf planet" by first time.

Other cool features of Eris They are:

• 2326 ± 12 km diameter
• Orbital period: 560.90 Earth years.
• Rotation period: 25 hours. The day in Eris we could say that it lasts approximately the same as the terrestrial.
• Satellite: It has 1 satellite called Dysnomia, which takes 16 Earth days to complete a full orbit around Eris. In fact, Eris and her moon Dysnomia are currently the most distant natural objects in the entire Solar System.
• Atmosphere: sometimes freezes due to lack of sunlight.
• Surface: Scientists believe that the surface of Eris is rocky, similar to that of Pluto.
• Surface temperature: The average temperature is estimated to be -231 ° C, between -218.15 and -243.1 ° C.

Pluto is the second closest dwarf planet to the Sun and the second largest dwarf planet. The main characteristics of Pluto are:

• Satellites: Pluto has five known moons, Charon, Styx, Nix, Kerberos, and Hydra. Charon is Pluto's largest moon, and it is quite large compared to the size of its planet. Charon and Pluto orbit around a common point that lies between them and, as with the Earth's Moon, Pluto always "sees" the same face of Charon.
• Orbital period: 246.04 Earth years.
• Pluto's orbit is eccentric and inclined. Furthermore, it is chaotic and unpredictable. Scientists have only been able to predict its orbital trajectory for the next 10-20 million years, beyond that it is unknown what its location may be.
• Surface: Pluto's surface is believed to be 50–70% rock and 30–50% ice mass. In its interior it is believed that there is a solid rocky core, surrounded by a blanket of water ice and a surface of frozen nitrogen.
• Atmosphere: unstable. When Pluto is closer to the Sun, the ice surface thaws and a thin atmosphere of nitrogen, methane, and carbon monoxide forms. As it moves away from the Sun, it freezes back into its solid state.

Image: Storyboardthat

Another of the dwarf planets of the solar system is Makemake and, in addition, it is the only dwarf planet that does not have its own orbiting moon, which means that its mass can only be estimated by scientists. Other curious facts about Makemake are:

• Extremely low temperature: Makemake's surface temperature is estimated to be −243.2 ° C.
• Surface: Makemake is covered in methane, ethane, and possibly nitrogen ice.
• Orbital period: 309.88 Earth years.

Haumea is the least spherical of all dwarf planets and has a characteristic elongated shape. In addition, it is one of the denser. Its peculiar shape is believed to be due to fast rotation (similar to the way a water balloon stretches when thrown with a twist). Other characteristics of the dwarf planet are:

• Satellites: Haumea has two moons, Hi’iaka and Namaka. Its origin is believed to be similar to that of the Earth's Moon: due to a collision of a large object with Haumea and its consequent fragmentation.
• Rotation period: 3.9 Earth hours. It is one of the fastest spinning large objects in the solar system.
• Surface: it is believed to be made of rock with a thick layer of ice that covers it.
• Temperature: the surface temperature is believed to be -241 ° C.

Ceres is the only dwarf planet that lies within the asteroid belt, between the orbits of Mars and Jupiter, while the other dwarf planets are in the farthest part of our Solar System, near the Kuiper belt. Other features of Ceres are:

• Ceres has been considered a planet (1801 until the 1850s) and an asteroid (1850s until 2006), before becoming a dwarf planet.
• The presence of water ice on Ceres has led to speculation that there could be life. In fact, scientists believe that Ceres' ice sheet may contain up to 200 million cubic kilometers of water, that is, more fresh water than can be found on the planet Land.
• Surface temperature: -105 ° C
• Orbital period: 4.6 Earth years.
• Rotation period: 9 hours and 4 minutes.

Image source: El Periódico

If you want to read more articles similar to What are the dwarf planets of the solar system, we recommend that you enter our category of Astronomy.

• Deutsche Presse Agentur (August 22, 2006) Astronomers divided over "planet" definition. Recovered from https://www.rawstory.com/news/2006/Astronomers_divided_over_planet_def_08222006.html
• NASA (October 31, 2018) Space Shorts: What is a Dwarf Planet? Recovered from https://solarsystem.nasa.gov/resources/336/space-shorts-what-is-a-dwarf-planet/
• Wikipedia (March 20, 2020) Eris (dwarf planet) Recovered from https://es.wikipedia.org/wiki/Eris_(planeta_enano)
• The Planets (s.f) Dwarf Planets Facts. Recovered from: https://theplanets.org/dwarf-planets/