NCERT Class 6 Geo Chap – 1 – Page 3
Venus Mercury Earth Mars Jupitar Saturn Uranus Neptune Asteroid Belt Comparision of Inner Planets Comparision for Outer Planets Orbits

Venus

Venus is similar in structure and size to Earth, and is sometimes called Earth's evil twin. Its thick atmosphere traps heat in a runaway greenhouse effect, making it the hottest planet in our solar system with surface temperatures hot enough to melt lead. Its the 2nd Planet from the Sun

Notable Features

⇒ Venus appears bright white from space because of its thick clouds that reflect sunlight. However, if you were standing on Venus, everything would look orange because of the thick atmosphere that filters sunlight.

⇒ Venus is the second brightest natural object in the night sky after the Moon. Venus is the first celestial body to become visible in the sky at evening and is the last one to disappear from the sky at sunrise. Venus is called the Evening Star when it appears in the western sky after sunset. It's called the Morning Star when it appears in the eastern sky before sunrise

⇒ The surface of Venus is covered in volcanic plains, valleys, mountains, and impact craters.

⇒ Venus's atmosphere is 96% carbon dioxide and 3% nitrogen. It has 90 times the atmospheric pressure of Earth

Mercury

Mercury, the smallest planet in our solar system, it looks similar to Earth's moon, with a surface covered in impact craters.

Notable Features:

⇒ Mercury's surface is mostly greyish-brown, with bright streaks called "crater rays". These rays are formed when asteroids or comets hit the surface, throwing crushed rock that falls back to the surface.

⇒ Mercury has gigantic cliffs, or scarps, that climb thousands of feet above the terrain. These features are the result of the planet's crust shrinking after it cooled

⇒ Atmosphere: Mercury has almost no atmosphere

Earth

We already Know about our Planet don't We?

Mars

Mars, also known as the Red Planet, appears as a bright red dot in the night sky. Its the Fourth Planet from the Sun

Notable Features

⇒ Color: Mars appears red because of the iron oxide (rust) in its soil, dust, and regolith.

⇒ The surface of Mars is rocky and covered in craters, volcanoes, dry lake beds, and canyons.

⇒ Dust storms: Mars has some of the largest dust storms in the solar system, which can cover the entire planet.

⇒ Atmosphere: Mars has a thin atmosphere that's mostly carbon dioxide and contains very little oxygen.

Jupitar

Jupitar the biggest planet in our solar system but being a gas giant lacks a surface . It is the fifth planet from the Sun. Jupiter's thick clouds create the appearance of stripes. The planet's fast rotation creates strong jet streams that separate the clouds into dark belts and bright zones.

Notable Features

⇒ Great Red Spot: A giant, swirling, red storm that looks like a hurricane. It's the largest and longest lasting storm in the Solar System.
⇒ Rings :Jupiter has three thin rings made of dust that are hard to see.
⇒ Colors; Jupiter's clouds are red, brown, yellow, and white. The planet's vivid colors may be plumes of sulfur and phosphorus-containing gases rising from its interior. 

Saturn

Saturn is a giant gas planet with a yellowish-brown color and a ring system. Saturn is yellowish-brown due to its atmosphere, which is made up of hydrogen, helium, ammonia, phosphine, water vapor, and hydrocarbons

Notable Features

⇒ Rings: Saturn's rings are made of chunks of ice and rock, and are made up of many tiny ringlets

⇒ Shadow: The shadow of Saturn on its rings adds to the 3D appearance of the planet

⇒ Spokes: The rings can have spokes that are made of tiny ice particles that are lifted by an electrostatic charge

Uranus

Uranus looks blue-green with faint rings. Its blue-green color comes from methane gas in its atmosphere. It's the seventh planet from the Sun and the third largest planet in our solar system.

Notable Features

⇒ Rings: Uranus has 13 known rings, with the inner rings being narrow and dark and the outer rings being brightly colored and easier to see.

⇒ Atmosphere: Uranus's atmosphere is mostly hydrogen and helium, but it also has methane. The atmosphere looks quite calm, with very few clouds.

⇒ Rotation: Uranus rotates on its side, at a nearly 90-degree angle from the plane of its orbit. It also rotates in the opposite direction as most other planets.

Neptune

Neptune is an ice giant planet that appears blue and has a smooth surface because it's made of gas. Neptune is the eighth and most distant major planet from the Sun

Notable Features

⇒ Rings: Neptune has six rings, but they're very hard to see. A 2022 image taken by the Webb's Near-Infrared Camera (NIRCam) brought the planet's rings into focus for the first time in over 30 years.

⇒ Atmosphere: Neptune's atmosphere is made of hydrogen, helium, and methane.

⇒ Other features: Neptune has the Great Dark Spot, Scooter, and the Small Dark Spot

Asteroid Belt

The asteroid belt is a torus-shaped region in our solar system that contains millions of asteroids orbiting the sun between the orbits of Mars and Jupiter.

Comparision of Inner Planets

Parameters  Definition as a Whole Mercury Venus  Earth  Mars
Surface Density  (gm/cm3) Inner or Terrestrial planets: Smaller and rockier. Have relatively high densities. 5.4 5.2 5.5 (Highest) 3.9
Mass (Kg) How massive a planet is has more to do with its composition and density.The four outer planets, called the gas giants, collectively make up 99% of the mass known to orbit the Sun.  3.3×1023 kg  4.8685 x 10^24 kg  5.9736 x 10^24 kg  6.4185 x 10^23 kg
Size (Radius) A planet's size is not necessarily proportional to its mass. The size of a planet is determined by its composition and rotation speed. while Jupiter is 318 times as massive as Earth, its composition and density mean that it is only 11.21 times Earth's size.  2,440 km  6,052  6,371  3,390 km
Surface Gravity  Gravitational force a planet exerts upon an object at the planet's surface is proportional to its mass and to the inverse of the planet's radius squared.  3.7 M/sec^2  8.9 M/sec ^2  9.81 m/s2 3.7 M/sec ^2
Atmosphere Generally inner planets have thin or very Little atmosphere with the exception of Venus  Thinnest  Thickest  Thicker to Mars  Thiiner to Earth
Temperature Inner planets are hotter because of their closeness to the sun  +427  +480(Highest)  +22  -23
Moons and Rings Inner plaets have no or few moons.They do not have Rings  0  0  1  2
Brightness Inner planets are Brighter
Distance Distance from Sun in (AU) 0.4 0.7 1 1.5
Type of Rotation and Period Inner Planets Slower and Rotate Anti Clock Wise except Venus  58 days  243 days  23:56 hrs  1.025 days
Period of Revolution  Inner planets have Smaller orbits and  move faster around the Sun  87 days  224 days  365 days  687 days (Highest)

Comparision for Outer Planets

Parameters  Definition as a Whole Jupitar Saturn Uranus Neptune
Surface Density  (gm/cm3) Outer planets: Larger and and are made up of gas. composed of low-boiling-point materials 1.3 0.7 1.3 1.6
Mass (Kg) How massive a planet is has more to do with its composition and density.The four outer planets, called the gas giants, collectively make up 99% of the mass known to orbit the Sun. 1.899 x 10^27 kg (Highest) 5.685 x 10^26 kg  8.682 x 10^25 kg  1.024 x 10^26 kg
Size (Radius) A planet's size is not necessarily proportional to its mass. The size of a planet is determined by its composition and rotation speed. while Jupiter is 318 times as massive as Earth, its composition and density mean that it is only 11.21 times Earth's size. 69,911 km 58,232 km 25,362 km  24,622 km
Surface Gravity  Gravitational force a planet exerts upon an object at the planet's surface is proportional to its mass and to the inverse of the planet's radius squared. 24.9 M/sec^2 (Highest)  10.4 M/sec ^2  8.8 m/s2 11.1 M/sec ^2
Atmosphere Generally outer planets have a very thick atmosphere Thicker to Saturn Thicker to Uranus  Thicker to Neptune  Less Thicker to Uranus
Temperature Outer planets are colder because of they are further away from Sun  -150  -180  -214 -220
Moons and Rings Outer Planets have Numerous moons . Their moons are, however, solid. They have extensive Ring Systems 79 82  27 14
Brightness Outer planets are Less bright as sun’s light barely reach them
Distance Distance from Sun in (AU) 5.2 9.6 19.2 30
Type of Rotation and Period Outer Planets Rotate Faster Anti Clock Wise except Uranus  9.9 hrs (Fastest) 10.7 hrs  17 hrs  16 hrs
Period of Revolution Outer planets have Longer orbits and thus tae more time to move around the Sun  11.9 years  29 years  84 years  164 years

Orbits

An orbit in the solar system is the curved/elliptical path that an object takes around another object due to gravity. The object in orbit is called a satellite, which can be natural or human-made. Orbits in the solar system are not visible

Here are some examples of orbits in our solar system:

⇒ Earth's orbit: Earth orbits the sun, taking about one year to complete a full orbit.

⇒ Moon's orbit: The moon orbits Earth, taking about one month to complete a full orbit.