If you look up and see a wandering star it may actually be a planet.
There are 9 planets in our solar system. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
The Sun is at the center with 99.85% of the mass and is very bright. It is not as big as other stars like Betelgeuse. All the planets combined are about 0.14% of the mass of the solar system. Comets are about .02%.
These pictures of solar system show relative size of sun and planets:
Planets: Diameter and distance from Sun:
Mercury 4,879 km 57,909,227 km
Venus 12,104 km 108,209,475 km
Earth 12,742 km 149,598,262 km
Mars 6,779 km 227,943,824 km
Jupiter 139,822 km 778,340,821 km
Saturn 116,464 km 1,426,666,422 km
Uranus 50,724 km 2,870,658,186 km
Neptune 49,244 km 4,498,396,441 km
Pluto, Eris, Makemake, Haumea, Sedna are dwarf planets.
Here is an infographic that I made showing size of planets compared to the Sun and the composition:
Celestial bodies resemble a planet but have failed to achieve the certain physical and technical characteristics. There are 5 dwarf planets currently known:
- Pluto – the former 9th planet but due to its physical characteristics that differ from the other planets it had become and re-classify as a dwarf planet.
- Eris – it is located around the orbit of Neptune, it’s much smaller than Pluto and can finish one trip around the Sun every 557 years. Due to its distance there has not been enough data and information on the inner structures of the Eris.
- Ceres – located between the orbits of Mars and Jupiter, its physical structure resembles the moon with icy rock formations and researchers suggest that it might have a body of ocean hidden within the ice layers.
- Makemake – located beyond the orbit of Neptune specifically the Kuiper Belt which is a ring of ice debris and it takes 300 years to complete a trip around the Sun.
- Haumea – is discovered also in Kuiper Belt and has 2 moons and it is an egg shape planet.
Here is a photo of Mercury:
Average orbital speed 47.36 km/s
Mean diameter 4880 km
The planet Mercury is on the inner planet along with the planet Venus and Earth, its physical characteristics resemble the Moon because its surface is cratered and bombarded continuously by asteroids for billions of years, while its outer core is comprised of iron sulfide, with outer liquid core layer and the solid inner core. Despite being closest to the Sun the planet Mercury cannot retain heat due to the lacking of atmosphere, it also has a longer rotation consisting of 59 days and a huge magnetic field similar to Earth but on a more powerful scale.
Venus is made of hot gas and look like this:
Surface temp 900 degrees F
Diameter 12,100 km
It is named as the hottest surface planet in the solar system, due to its dense atmosphere made up 96% carbon dioxide. The clouds inside the planet are made up of sulfuric acid.
The Earth is the 3rd rock in orbit around the Sun:
Earth’s atmosphere is made up of nitrogen and oxygen. The surface is 70% covered by water.
Mars, aka the red planet:
Orbital speed 24 km/s
Radius 3389 km
The Iron Oxide that can be found on the planet’s surface makes the entire physical appearance a distinct red color, recent explorations show that there is evidence that their bodies of water in the past. Compared to the planet Earth it is approximately half of the diameter with the gravitational pull.
Image of Jupiter:
Orbital speed 13.07 km/s
Radius 69,811 km
The overall structure of the planet Jupiter is primarily comprised of hydrogen and helium making the planet a gas giant due to the fact that it is lacking a well-defined surface area. It is considered to be the oldest planet in the solar system due to this it has amassed a magnetic field 14x stronger than the Earth has and is usually the brightest planet in the sky.
Orbital speed 9.58 km/s
Radius 58,232 km
The planet is composed of iron-nickel and rock silicon compounds, but its best known for its ring system which is made from ice particles that orbit around the planet.
Uranus is the 7th:
Orbital speed 6.8 km/s
Radius 25,362 km
It is the coldest planet in the solar system with a temperature of -224 and much heavier cloud impossible for sunlight to penetrate.
Neptune is the 8th:
Orbital speed 5.43 km/s
Radius 24,622 km
It has an atmosphere composed of hydrogen and helium along with hydrocarbons and nitrogen.
Pluto was the 9th, because now is considered a dwarf planet.
Orbital speed 4.74 km/s
Radius 1183 km
Asteroids – are small rocky objects that float and orbit around the Sun. The majority of them are located in the asteroid belt located between the orbits of Mars and Jupiter, they are considered to be leftover materials that did dissolve in the Sun and from the formation of the Solar system.
Some of these asteroids will pass Earth, others go inside the atmosphere and are dissolved due to the heat, and other asteroids have directly impacted the planet such as what happened in the Cretaceous period where the impact of an asteroid had completely annihilated the entire species of dinosaurs.
Comets – are made of cosmic snowballs of frozen gases such as rock, and dust that had orbited around the Sun, usually they are frozen can be the size of a small village. When we see a comet passing through the Sun it begins to get warm and releases amounts of gases, it is called outgassing this is the visible atmosphere being produced which sometimes human call a shooting star.
Oort Cloud – is the concept by Dutch astronomer Jan Oort, according to his study, the Oort cloud is located far beyond the current location of the Dwarf planet Pluto and the Kuiper belt. It is believed that it is a giant spherical shell that covers the entire Sun, planets, and the entire solar system in place making it like a thick bubble that is made from icy comet objects.
Kuiper Belt – is a disc-shaped region located outside the solar system, it extends from the orbit of Jupiter and Neptune, like the asteroid belt, but on a larger size. It comprises smaller bodies that were considered to be leftovers when the solar system was formed, basically, it consists of asteroids, frozen debris, and it is considered to be the home of the dwarf planets.
The Interplanetary Medium consists of thinly mass-energy that is scattered across the entire solar system such as the magnetic and electric forces inside the planets. It is usually made from hydrogen, plasma gas, and electrically charged particles from the Sun such as cosmic rays, ultraviolet light, and dust particles.