Atmospheric Meteor Explosions & Planetary Defence

Relevance: GS Paper III — Science & Technology (Space, awareness in space)

Source: NASA / Associated Press, 2026

1 · Context

A roughly 1-metre-wide meteor entered Earth’s atmosphere near the New Hampshire–Massachusetts border in the United States. It produced a bright daytime fireball visible from Delaware to Montreal and a double sonic boom recorded by the U.S. Geological Survey. NASA confirmed it was a natural space rock.

2 · The meteor lifecycle

FROM SPACE ROCK TO GROUND · LIFECYCLE

METEOROID · in space A small rocky/metallic body travelling through outer space.

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METEOR · in the atmosphere (~100 km) A bright streak — burns due to atmospheric friction. Recent U.S. meteor: ~120,700 km/h.

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FIREBALL · airburst (~60 km) Exceptionally bright meteor that explodes mid-air. Energy: ~300 tonnes of TNT equivalent. Generates sonic boom.

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METEORITE · reaches the ground Surviving fragment that strikes Earth’s surface. Forms impact craters — e.g. Lonar (Maharashtra).

3 · Key terms — 

• Meteoroid: a small rocky/metallic body in outer space.
• Meteor: the bright streak when a meteoroid burns in the atmosphere.
• Bolide / Fireball: an exceptionally bright meteor that often explodes mid-air.
• Meteorite: the fragment that survives and strikes the ground.
• Sonic boom: shockwave when an object travels faster than sound.

4 · Major impact craters — global & Indian

• Chicxulub Crater (Yucatán, Mexico) — linked to the mass extinction of dinosaurs.
• Vredefort Crater (South Africa) — the oldest and largest verified impact crater on Earth.
• Lonar Crater (Maharashtra) — world’s only hyper-velocity impact crater in basalt rock; a Ramsar site.
• Dhala Crater (Madhya Pradesh) — India’s oldest and largest impact structure.
• Ramgarh Crater (Rajasthan) — recognised as a Geo-heritage site by the Geological Survey of India.

VALUE BOX  Order to remember: Meteoroid (space) → Meteor (burning) → Bolide (airburst) → Meteorite (ground). NASA’s Planetary Defence Coordination Office (PDCO): detects Near-Earth Objects (NEOs) within 8 million km of Earth. DART Mission (Double Asteroid Redirection Test): NASA proved ‘kinetic impactor’ technology by deflecting the asteroid moonlet Dimorphos. ISRO’s Project NETRA (Network for Space Object Tracking and Analysis): India’s early-warning system, primarily for space-debris surveillance. International Asteroid Warning Network (IAWN) and UN COPUOS: India is an active partner.

MCQ · PRELIMS PRACTICE

Consider the following statements regarding atmospheric meteors and planetary defence:

1. A meteorite is a small rocky body travelling through outer space, while a meteoroid is the surviving fragment that strikes the Earth’s surface.
2. Lonar Crater in Maharashtra is the world’s only known hyper-velocity impact crater formed in basalt rock and has been notified as a Ramsar site.
3. ISRO’s Project NETRA is an early-warning system that primarily tracks space debris and other space objects to safeguard Indian satellites.

Which of the statements given above 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

Statement 1 — Incorrect (the trap). The two definitions are reversed. A meteoroid is the small rocky body in outer space; a meteorite is the surviving fragment that strikes the ground.

Statement 2 — Correct. Lonar Crater in Maharashtra is the world’s only hyper-velocity impact crater formed in basalt, and is a Ramsar site.

Statement 3 — Correct. Project NETRA is ISRO’s early-warning system; its primary role is space-debris surveillance.