Other Heavenly Bodies of the Solar System

Some heavenly bodies revolve around planets. These are called satellites. Satellites do not make their own light. They get light from the sun. Like planets, satellites rotate around their respective axes.

• The moon is the satellite of the earth. It does not have an atmosphere. Its periods of rotation and revolution are both 27.3 days.
• Except for Mercury and Venus, all other planets have satellites, but in varying numbers.

Satellite

Asteroids are small space rocks that orbit the Sun, just like planets. When the solar system was forming, many small rocks and particles didn’t become planets. These are now called asteroids.

• Most asteroids are found in a region called the Asteroid Belt.
• The asteroid belt is located between the planets Mars and Jupiter.
• Asteroids are much smaller than planets and have irregular shapes (not round like planets).
• Some asteroids are only a few meters wide, while others can be hundreds of kilometres across!
• They are made of different materials like rock, metal, and sometimes ice.
• Even though there are many asteroids, they are spread out in space, so they don’t often collide with each other.

Asteroids

These are small celestial bodies that revolve around the sun, just like planets, but they are smaller than regular planets. Dwarf planets move around the sun on their own in a path called an orbit. 

• Pluto is the most well-known dwarf planet. It takes around 248 years to complete its revolution around the sun.
• Pluto completes one rotation in about 6.38 days, which means one full day on Pluto is almost six and a half Earth days long.
• Dwarf planets are smaller than planets like Earth or Mars and don't clear their orbit of other debris, which is one reason they are not called planets.

Dwarf planet

Comets are space objects that revolve around the sun, like planets. They are formed from frozen gases, ice, and dust particles.

• Comets are part of our solar system and move in large elliptical (oval-shaped) orbits around the sun.
• In ancient times, people thought comets brought bad events or misfortune when they appeared in the sky.
• When comets are far from the sun, they look like small points in the sky. But when they come closer to the sun, they become more visible.
• As comets get closer to the sun, the heat turns their frozen matter into gas.
• The gases from the comet are pushed away from the sun, forming a long, feathery tail that can be seen from Earth.
• Because comets have long orbits, they are only seen in the sky after a long time.

Types of comets:

1. Long-period comets: These take more than 200 years to go around the sun.
2. Short-period comets: These take less than 200 years to complete one orbit.

Halley's Comet:

Halley's Comet last appeared in 1986 and will return in about 76 years. It was first observed in 1910. Halley's Comet is about 16 kilometres long and 7.5 kilometres wide.

Halley’s comet

1. Meteoroids: These are small pieces of rock or metal floating in space. They can be as small as a grain of sand or as big as a boulder.
2. Meteor: When a meteoroid enters Earth's atmosphere, it moves quickly and rubs against the air. This friction causes the meteoroid to heat up and glow, creating a bright streak of light. This streak is called a meteor or shooting star. It looks like a star falling from the sky, even though it's not a star.
3. Meteor fall: When you see a shooting star, it's called a meteor fall. Most of these meteors come from rocky pieces that break off from the asteroid belt, which is a region between the planets Mars and Jupiter.
4. Burning in the atmosphere: Smaller meteors burn up completely before they reach the ground because the friction with the air makes them so hot that they disappear.
5. Meteorites: Sometimes, a meteor does not burn up entirely and falls to the surface of the Earth. This piece of space rock is called a meteorite.

It is believed that Lonar Lake in India was formed when a large meteorite hit the Earth many years ago, creating a big crater that was filled with water. Meteors and meteorites can also fall on other planets and moons, not just on Earth. 

Lonar Lake of Maharashtra