Asteroids and Meteoroid

Topics

• Asteroids
• Asteroid Belt
• Meteoroid
• Meteors
• Meteorites
• Comets

 

What is Asteroids?

Asteroids are small rocky celestial bodies that revolve around the Sun, like other planets.

• Smaller than a planet.
• They are also called ‘Minor Planets’.
• There are lots of asteroids in the solar system.
• Larger asteroids are called Planetoids.
• They are mainly found in Asteroid Belt.

Asteroid Belt: It is in between the planets Mars and Jupiter.

Size of Asteroids:

The diameter of the asteroids varies from 100 km to a size of a pebble.

 

What are Meteoroids?

There is a bright streak of light flashing seen often in the sky during night for a few seconds. They are called as ‘shooting stars’.

They are the removed pieces of rocks mainly from the Asteroid belt. They are called Meteoroids before they enter into our atmosphere.

What are Meteors?

They enter into the atmosphere with great speed. But most of them are burnt when they enter into the atmosphere. After entering into our atmosphere, they are called as Meteors.

What are Meteorites?

Sometimes meteoroids do not burn fully and they fall on the earth and make craters. When they land on the Earth, they are called Meteorites.

Examples for Meteorite Fall: Meteor crater in Northern Arizona.

 

What are Comets?

Comets are the most exciting heavenly bodies and have ever been the objects of man’s curiosity as well as fear.

The word Comet is derived from the Greek word Aster Kometes meaning ‘Long Haired Star’.

They are made up of small ice particles and meteoric fragments.

They revolve around the Sun. But their orbits are irregular.

Sometimes they get very close (Perihelion) to the sun and in other times they go far away (Aphelion) from the sun.

The best-known Comet, Halley’s Comet, appears once in every 76 years. The Halley’s Comet was seen last in 1986 and it will be seen again on 28th July 2061.

 

Aphelion of the Earth:

• Ap: Away/Farthest
• Helion: Sun
• Distance: 152 Mn Km
• 4th July

 

Perihelion of the Earth:

• Peri: Nearest/Closest
• Helion: Sun
• Distance: 147 Mn Km
• 3rd January

 

More Details: Aphelion & Perihelion

 

Practice Questions:

What are the differences between Asteroids and meteoroids?

What is Aphelion and Perihelion?