Description

Disclaimer: Copyright infringement not intended.

Context

NASA and the European Space Agency are tracking asteroid 2024 YR4, which has a 1.6% chance of impacting Earth on December 22, 2032, highlighting the need for planetary defence monitoring.

About Asteroids

Asteroids are remnants of planetary formation
that failed to coalesce because of the gravitational interference of Jupiter.
They circle the Sun in a zone lying between Mars and Jupiter. The circular chain of asteroids is called the asteroid belt. It lies between 2.3 and 3.3 AU from the Sun.
Asteroids (planetoids― another term for an asteroid) are composed mainly of refractory rocky and metallic minerals, with some ice
Unlike planets, asteroids are irregularly shaped and much smaller. They range in size from hundreds of kilometres across to microscopic.
They are remnants from the early solar system, formed about 6 billion years ago.
Some asteroids cross Earth's orbit and are classified as Near-Earth Objects (NEOs), which are closely monitored for potential collisions.

Potential Destruction from 2024 YR4

Torino scale is a rating system that helps astronomers and the public understand the risk of a near-Earth object (NEO) colliding with Earth.
The scale is named after Turin, Italy, where it was first presented at an international conference in 1999.
The scale uses a number from 0 to 10, with higher numbers indicating a greater risk.
The NASA JPL Center for Near-Earth Object Studies (CNEOS) has currently rated the 2024 YR4 a 3 on a scale from 0 to 10.
If 2024 YR4 crashes into Earth, it is expected to release 8 to 10 megatons of energy.
The scale is color-coded to help convey the level of risk.

Asteroid Deflection: Strategies to Prevent Potential Collisions

Space agencies like NASA are developing planetary defence strategies to prevent catastrophic asteroid collisions with Earth.

The DART Mission

NASA’s Double Asteroid Redirection Test (DART), in collaboration with the Johns Hopkins Applied Physics Laboratory, was the first planetary defence mission.

Sources:

INDIAN EXPRESS

PRACTICE QUESTION

Q. Recently, asteroid 2024 YR4 was identified as a potential threat to Earth. Consider the following statements regarding near-Earth objects (NEOs):

All near-Earth objects (NEOs) are classified as potentially hazardous asteroids.
The Torino Scale is used to assess the impact risk of asteroids.
Planetary defence strategies primarily focus on deflecting asteroids away from Earth's trajectory.

Which of the statements given above is/are correct?

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

Answer: (b) 2 and 3 only

Explanation:

Statement 1 is incorrect – Not all NEOs are classified as potentially hazardous asteroids (PHAs). An asteroid must meet specific size and proximity criteria to be considered hazardous.
Statement 2 is correct – The Torino Scale is a tool used to categorize the likelihood and potential consequences of an asteroid impact.
Statement 3 is correct – Planetary defense efforts, such as NASA’s DART mission, focus on deflecting asteroids using kinetic impactors and other mitigation strategies.

Thus, the correct answer is (b) 2 and 3 only.