Why we shouldn’t worry (too much) about an asteroid hitting Earth

Sub : Sci

Sec: Space sector

Context:

2024 ON, an asteroid the size of the Eiffel Tower and shaped like a peanut, was deemed potentially hazardous but posed no actual threat to Earth.
It measured 370 meters in diameter and traveled at 40,000 kilometers per hour.
Despite dramatic headlines, astronomers calculated that 2024 ON would pass by Earth at a safe distance of one million kilometers, more than twice the distance to the moon.

Near-Earth Objects (NEOs)

Definition:
- According to the United Nations Office for Outer Space Affairs, NEOs are asteroids or comets that pass close to Earth’s orbit, with a perihelion (closest distance to the sun) of less than 195 million kilometers.
- Earth’s orbit is 150 million kilometers from the sun, meaning NEOs are within our solar neighborhood.
Known NEOs:
- Scientists have cataloged around 34,000 NEOs, and none of the larger ones are currently on a collision course with Earth.

Asteroid Impact Likelihood:

Smaller NEOs:
- Tiny NEOs hit Earth daily, but larger impacts are rare. An asteroid the size of 2024 ON might hit Earth once every 10,000 years.
Larger Asteroids:
- Around 100 tons of space debris hits Earth daily, though it consists mostly of tiny rocks that don’t cause harm.
- Objects larger than 1 kilometer in diameter, like the asteroid that caused the dinosaur extinction, might impact Earth every 260 million years.
- Only 5% of such large objects remain undiscovered.
- Even smaller NEOs, around 40 meters in width, can cause significant damage if they enter Earth’s atmosphere at high speeds.

Finding and Tracking NEOs

NEOWISE telescope has discovered over 158,000 NEOs before it was retired in 2024.
Its successor, the NEO Surveyor, is set to begin in 2027, aiming to find more hazardous asteroids.
The upcoming Vera Rubin Observatory (Ground-Based Telescope) in Chile will provide a time-lapse map of the universe, significantly improving asteroid discovery rates.
The ESA’s Flyeye telescopes will also contribute to tracking asteroids by making wide-field observations of the night sky.
Detecting NEOs is difficult because it’s hard to gauge how far away objects are from Earth.

NASA’s DART Mission:

In 2022, NASA successfully tested its Double Asteroid Redirection Test (DART) by crashing a spacecraft into an asteroid to change its trajectory.
ESA will launch Hera in October 2024 to further study DART’s impact and help refine planetary defense strategies.
The asteroid Apophis, once considered a significant threat, will pass close to Earth in 2029, but updated calculations show it won’t hit the planet.

Source: IE