New Delhi: Many times, asteroids pass by Earth without colliding with the planet. However, asteroids may pose a threat to Earth in future. NASA's Double Asteroid Redirection Test (DART) spacecraft, which was launched Wednesday, is a planetary defense-driven test that will crash into an asteroid to demonstrate a method of asteroid deflection.
Asteroids, comets, and meteors are planetary objects in the solar system orbiting the Sun. Asteroids are sometimes called minor planets, and are rocky remnants left over from the early formation of the solar system 4.6 billion years ago. Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun, and are the size of a small town when frozen. Meteors, also known as shooting stars, are pieces of dust and debris from space that burn up in Earth's atmosphere.
In a recent video released by NASA, Near Earth Asteroid Expert Dr. Ryan Park explained the difference between these planetary objects. He said asteroids are rocky, comets are icy, and meteors are the shooting stars that we see in the sky.
What Are Asteroids?
Park said an asteroid is a small rocky object, which appears as a point of light when seen in a telescope.
Most asteroids are found in a ring between the orbit of Mars and Jupiter, called the asteroid belt. Asteroids can be of varying shapes, such as round, elongated, and some asteroids even have a satellite.
Comets Are Icy
A comet, unlike an asteroid, is composed of ice and dust.
When a comet gets close to the Sun, Park explained, its ice and dust begin to vaporise.
When viewed in a telescope, the comet appears fuzzy and can have a tail sometimes.
Meteors Also Called Shooting Stars
A meteorite is a small piece of asteroid that is typically pebble-sized. It could be a little smaller, or a little larger, and is often created from a collision.
When a meteorite gets close to the Earth, and enters the Earth's atmosphere, it is called a meteor. Since a meteor enters the Earth's atmosphere at a very high speed, it burns up and produces a streak of light called a shooting star. If a meteor survives the burn and lands on the ground, it is called a meteorite, Dr. Park said.
Watch the video here: