Context:
- NASA had earlier identified Asteroid 2024 YR4 as a potential celestial threat, with preliminary estimates indicating a 3.8% probability of impacting the Moon on December 22, 2032.
- Updated orbital calculations and refined trajectory data now suggest that YR4 is unlikely to collide with either Earth or the Moon.
- The episode highlights advances in asteroid tracking, impact prediction, and planetary defence mechanisms.
Key Highlights:
About Asteroid 2024 YR4
- Classified as a Near-Earth Object (NEO) and Potentially Hazardous Asteroid (PHA).
- Approximate size: ~68 metres wide.
- Categorised as hazardous due to:
- Its orbital proximity to Earth
- Its impact energy potential, not due to immediate threat.
Impact Probability and Updated Assessment
- Initial estimates flagged a lunar impact risk.
- Latest observations show:
- Negligible probability of Earth or Moon collision.
- Reduced uncertainty due to continuous tracking.
Potential Impact Effects (Hypothetical)
- A Moon impact could release energy ~300 times that of the Hiroshima atomic bomb.
- Expected crater size: 500–2,000 metres in diameter.
- Visibility from Earth:
- Uncertain due to Moon’s brightness and observational conditions.
Relevant Prelims Points:
- Near-Earth Object (NEO):
- An asteroid or comet whose orbit brings it within 1.3 Astronomical Units (AU) of Earth.
- Potentially Hazardous Asteroid (PHA):
- NEOs larger than ~140 m or with close Earth approaches.
- Torino Scale:
- Measures impact hazard from 0 (no risk) to 10 (global catastrophe).
- YR4 rating: 1 – No immediate threat, routine monitoring.
- NASA Sentry Risk Table:
- Automated system for long-term asteroid impact risk assessment.
- Detection Systems:
- ATLAS, Pan-STARRS (ground-based telescopes)
- Space-based infrared and optical sensors.
Relevant Mains Points:
- Scientific and Technological Aspects (GS 3):
- Demonstrates advancements in orbital modelling, long-term trajectory prediction, and uncertainty reduction.
- Use of infrared vs optical detection:
- Infrared helps estimate size and composition.
- Optical data refines orbit and velocity.
- Disaster Management Perspective (GS 3):
- Asteroid impacts qualify as low-probability, high-impact disasters.
- Emphasises the need for planetary defence preparedness.
- Planetary Defence Initiatives:
- NASA’s DART Mission validated asteroid deflection technology.
- International coordination essential for early warning and response.
- Significance:
- Enhances global confidence in space situational awareness.
- Builds public understanding of cosmic risk governance.
- Way Forward:
- Strengthen global NEO monitoring networks.
- Expand international collaboration on planetary defence.
- Invest in early-warning systems, deflection research, and simulation exercises for cosmic hazards.