How often do Asteroids crash Into Earth?

• Thousands of small asteroids burn up in Earth’s atmosphere daily due to friction.
• The Chelyabinsk meteor (2013) exploded over Russia with 30 times the power of the Hiroshima bomb.
• Asteroids around 40 meters can cause regional destruction if they hit Earth.
• Large asteroids (1 km+ in size) can trigger global disasters, occurring about once every 260 million years.
• The Chicxulub asteroid (66 million years ago) led to the extinction of dinosaurs.

How Space Agencies prevent Asteroid Collisions?

• NASA and global space agencies work on planetary defense to prevent impacts.
• In 2022, NASA’s DART mission successfully changed asteroid Dimorphos’s trajectory using kinetic impact.
• Scientists explore 3 key methods for asteroid deflection:
  • Kinetic Impact:  Using spacecraft to hit an asteroid and alter its path.
  • Gravity Tractors:  Using a spacecraft’s gravity to pull an asteroid off course.
  • Nuclear Explosions: As a last resort, detonating a nuclear device near an asteroid to deflect or destroy it.

PYQ:

[2011] What is the difference between asteroids and comets?

1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material.
2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.
3. Comets show a perceptible glowing tail, while asteroids do not.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 1 and 3 only
(c) 3 only
(d) 1, 2 and 3